EP4320159A1 - Anticorps contre l'anticorps ilt4, anti-ilt4/pd-l1 bispécifique et ses utilisations - Google Patents

Anticorps contre l'anticorps ilt4, anti-ilt4/pd-l1 bispécifique et ses utilisations

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Publication number
EP4320159A1
EP4320159A1 EP22720158.9A EP22720158A EP4320159A1 EP 4320159 A1 EP4320159 A1 EP 4320159A1 EP 22720158 A EP22720158 A EP 22720158A EP 4320159 A1 EP4320159 A1 EP 4320159A1
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EP
European Patent Office
Prior art keywords
seq
variable region
chain variable
amino acid
set forth
Prior art date
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Pending
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EP22720158.9A
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German (de)
English (en)
Inventor
Tibor Keler
Joel Goldstein
Michael B. Murphy
Thomas O'neill
Laura A. Vitale
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Celldex Therapeutics Inc
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Celldex Therapeutics Inc
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Publication of EP4320159A1 publication Critical patent/EP4320159A1/fr
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/18—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans
    • C07K16/28—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants
    • C07K16/2803—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants against the immunoglobulin superfamily
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/18—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans
    • C07K16/28—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants
    • C07K16/2803—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants against the immunoglobulin superfamily
    • C07K16/2827—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants against the immunoglobulin superfamily against B7 molecules, e.g. CD80, CD86
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/505—Medicinal preparations containing antigens or antibodies comprising antibodies
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/20—Immunoglobulins specific features characterized by taxonomic origin
    • C07K2317/24—Immunoglobulins specific features characterized by taxonomic origin containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/30—Immunoglobulins specific features characterized by aspects of specificity or valency
    • C07K2317/31—Immunoglobulins specific features characterized by aspects of specificity or valency multispecific
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/30—Immunoglobulins specific features characterized by aspects of specificity or valency
    • C07K2317/33—Crossreactivity, e.g. for species or epitope, or lack of said crossreactivity
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/30—Immunoglobulins specific features characterized by aspects of specificity or valency
    • C07K2317/35—Valency
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/50—Immunoglobulins specific features characterized by immunoglobulin fragments
    • C07K2317/52—Constant or Fc region; Isotype
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/60—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/60—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments
    • C07K2317/62—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments comprising only variable region components
    • C07K2317/622—Single chain antibody (scFv)
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
    • C07K2317/76—Antagonist effect on antigen, e.g. neutralization or inhibition of binding
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/90—Immunoglobulins specific features characterized by (pharmaco)kinetic aspects or by stability of the immunoglobulin
    • C07K2317/92—Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value

Definitions

  • the inhibitory immune checkpoint receptor “immunoglobulin-like transcript 4”
  • ILT4 is a member of the non-catalytic tyrosine-phosphorylated receptor family which is expressed on immune cells (such as T cells, B cells, NK cells, dendritic cells, macrophages and mast cells). Like other receptors in this family, ILT4 contains a conserved sequence of amino acids in the cytoplasmic domain referred to as an immunoreceptor tyrosine-based inhibitory motif (ITIM). (Veillette et al. (2002) Annual Review of Immunology 20(1):669- 707). Binding and activation of ILT4 by its cognate ligands (HLA-G and HLA Class I in myeloid cells) has immunosuppressive effects through multiple mechanisms.
  • ITIM immunoreceptor tyrosine-based inhibitory motif
  • ILT4 is also found in tumor cells and stroma cells in the tumor microenvironment of various cancers and has been shown to modulate the biological behaviors of tumor cells, thus promoting their immune escape. (Gao et al. (2016) Biochimica et Biophysica Acta (BBA) - Reviews on Cancer 1869(2):278-285). Accordingly, the expression of ILT4 in several tumor types is associated with poor outcome.
  • Programmed death-ligand 1 is a 40kDa type 1 transmembrane protein associated with suppressing the immune system during particular events such as pregnancy, tissue allografts, autoimmune disease, and other disease states such as hepatitis. Normally the immune system reacts to foreign antigens that are associated with exogenous or endogenous danger signals, which triggers a proliferation of antigen- specific CD8+ T cells and/or CD4+ helper cells. Binding of PD-L1 to the receptor, Programmed cell death protein 1 (PD-1), transmits an inhibitory signal that reduces the proliferation of these T cells and can also induce apoptosis, which is further mediated by a lower regulation of the gene Bcl-2.
  • PD-1 Programmed cell death protein 1
  • PD-L1 is abundant in a variety of human cancers (Dong et al. (2002) Nat. Med. 8:787-9). The interaction between PD-1 and PD-L1 results in a decrease in tumor infiltrating lymphocytes, a decrease in T-cell receptor mediated proliferation, and immune evasion by the cancerous cells (Dong et al. (2003) J. Mol. Med.81:281-7; Blank et al. (2005) Cancer Immunol. Immunother.
  • novel antibodies which bind to human ILT4, and antigen binding fragments thereof (e.g., fragments such as an Fab, Fab', F(ab') 2 , Fv, or a single chain Fv).
  • Bispecific and multispecific constructs comprising such antibodies (or fragments) linked to at least one additional binding agent (e.g., a ligand, receptor/trap sequences, or an antibody or antigen binding fragment thereof) also are described, e.g., an additional antibody (or fragment) which binds to human PD-L1 and/or human PD-1.
  • the ILT4 antibodies (and fragments) and constructs of the present invention can be used in methods of inducing or enhancing an immune response and methods of treating a disease or condition (e.g., cancer).
  • the ILT4 antibody or antigen binding fragment thereof comprises heavy and light chain CDR1, CDR2 and CDR3 domains having the following sequences: (i) a heavy chain variable region CDR1 amino acid sequence selected from the consensus sequence: G Y T (I,M) H (SEQ ID NO: 21), or conservative sequence modifications thereof; (ii) a heavy chain variable region CDR2 amino acid sequence as set forth in SEQ ID NO:3, or conservative sequence modifications thereof; (iii) a heavy chain variable region CDR3 amino acid sequence selected from the consensus sequence: E R P G G S Q F I Y Y Y (P,A) (M,L) D Y (SEQ ID NO:22) , or conservative sequence modifications thereof; (iv) a light chain variable region CDR1 amino acid sequence selected from the consensus sequence: G Y
  • an exemplary ILT4 antibody is antibody 7A3 as described herein.
  • the ILT4 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 7A3.
  • the antibody or antigen binding fragment thereof comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 7A3 having the sequence set forth in SEQ ID NO:9, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 7A3 having the sequence set forth in SEQ ID NO:10.
  • the antibody or antigen binding thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:1, 3, and 5, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:6, 7 and 8, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding thereof comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:9.
  • the antibody or antigen binding thereof comprises a light chain variable region having the amino acid sequence set forth in SEQ ID NO:10.
  • the antibody or antigen binding fragment thereof comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:9 and SEQ ID NO:10, respectively.
  • the antibody or antigen binding thereof comprises a heavy chain having the amino acid sequence set forth in SEQ ID NO:25.
  • the antibody or antigen binding thereof comprises a light chain having the amino acid sequence set forth in SEQ ID NO:26.
  • the antibody comprises heavy and light chains having the amino acid sequences set forth in SEQ ID NO:25 and SEQ ID NO:26, respectively.
  • Another exemplary ILT4 antibody is antibody 7B1 as described herein.
  • the ILT4 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 7B1.
  • the antibody or antigen binding fragment thereof comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 7B1 having the sequence set forth in SEQ ID NO:19, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 7B1 having the sequence set forth in SEQ ID NO:20.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:11, 13, and 15, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs: 16, 17, and 18, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequences set forth in SEQ ID NO:19. In another embodiment, the antibody or antigen binding fragment thereof comprises a light chain variable region having the amino acid sequences set forth in SEQ ID NO:20. In another embodiment, the antibody or antigen binding fragment thereof comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:19 and SEQ ID NO:20, respectively. In another embodiment, the antibody or antigen binding thereof comprises a heavy chain having the amino acid sequence set forth in SEQ ID NO:27. In another embodiment, the antibody or antigen binding thereof comprises a light chain having the amino acid sequence set forth in SEQ ID NO:28.
  • the antibody comprises heavy and light chains having the amino acid sequences set forth in SEQ ID NO:27 and SEQ ID NO:28, respectively.
  • the ILT4 antibodies (or antigen binding fragments thereof) of the present invention comprise: (a) a heavy chain variable region amino acid sequence selected from the group consisting of SEQ ID NO:9, 19, 97, 98, 99, 103, 104, and 105, or a sequence at least 80% identical to any one of the aforementioned sequences; and / or (b) a light chain variable region amino acid sequence selected from the group consisting of SEQ ID NO:10, 20, 100, 101, 102, 106, 107, and 108, or a sequence at least 80% identical to any one of the aforementioned sequences.
  • the ILT4 antibodies of the present invention comprise: (a) a heavy chain amino acid sequence as set forth in SEQ ID NO:25, 27, or a sequence at least 80% identical to either sequence; and / or (b) a light chain amino acid sequence as set forth in SEQ ID NO:26, 28, or a sequence at least 80% identical to either sequence.
  • the sequences of the ILT4 antibodies or antigen binding fragments thereof can comprise the exact amino acid sequences as the antibodies described herein (e.g., antibodies 7A3 or 7B1).
  • the antibodies comprise sequences of antibodies 7A3 or 7B1 which include conservative sequence modification, yet still retain the ability of to bind ILT4 effectively.
  • sequence modifications may include one or more (e.g., 1, 2, 3, 4, 5, or 6) amino acid additions, deletions, or substitutions, e.g., conservative sequence modifications.
  • the antibodies comprise sequences which share at least 80% sequence identity to the sequences of antibodies 7A3 or 7B1. Sequences substantially identical to the ILT4 antibodies or antigen binding fragments described herein (e.g., at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences), are also encompassed by the invention.
  • the ILT4 antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:9, SEQ ID NO: 19, or a sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the ILT4 antibody or antigen binding fragment thereof comprises a light chain variable region comprising SEQ ID NO:10, SEQ ID NO:20, or a sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the ILT4 antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:9 and a light chain variable region comprising SEQ ID NO:10 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the ILT4 antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:19 and a light chain variable region comprising SEQ ID NO:20 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the ILT4 antibody or antigen binding fragment thereof comprises a heavy chain comprising SEQ ID NO:25, SEQ ID NO: 27, or a sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the ILT4 antibody or antigen binding fragment thereof comprises a light chain comprising SEQ ID NO:26, SEQ ID NO:28, or a sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the ILT4 antibody comprises a heavy chain comprising SEQ ID NO:25 and a light chain comprising SEQ ID NO:26 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the ILT4 antibody comprises a heavy chain comprising SEQ ID NO:27 and a light chain comprising SEQ ID NO:28 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • ILT4 antibodies or antigen binding fragments thereof that compete for binding with any of the antibodies (or fragments) described herein, or that bind the same epitope as any of the antibodies (or fragments) described herein, are also encompassed by the present invention.
  • the ILT4 antibody or antigen binding fragment thereof competes for binding to ILT4 with antibody 7A3 and/or antibody 7B1.
  • the ILT4 antibodies or antigen binding fragments exhibit one or more of the following properties: a. blocking ILT4 ligand (e.g., HLA-G ligand) binding to human ILT4; b. enhancing or increasing cytokine or chemokine release by human macrophages; c. potentiating the activation effects of LPS and IFN ⁇ on macrophages; d. promoting M1 macrophage polarization; e. binding to human ILT4 with an equilibrium dissociation constant Kd of 10 -9 M or less, or alternatively, an equilibrium association constant Ka of 10 +9 M -1 or greater; f. lack of cross-reactivity with other ILT family members; g.
  • ILT4 ligand e.g., HLA-G ligand
  • the present invention also provides bispecific constructs (or multispecific constructs) comprising the ILT4 antibodies or antigen binding fragments thereof linked to at least one additional binding agent (e.g., a ligand or an antibody or antigen binding fragment thereof, e.g., a PD-L1 or PD-1 antibody or antigen binding fragment thereof).
  • additional binding agent e.g., a ligand or an antibody or antigen binding fragment thereof, e.g., a PD-L1 or PD-1 antibody or antigen binding fragment thereof.
  • the bispecific construct comprises a PD-L1 antibody or antigen binding fragment thereof which comprises heavy and light chain CDR1, CDR2, and CDR3 amino acid sequences selected from the group consisting of: (a) heavy chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs: 59, 60, and 61, respectively, and light chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs:62, 63, and 64, respectively; (b) heavy chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs: 35, 36, and 37, respectively, and light chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs:38, 39, and 40, respectively; (c) heavy chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs: 41, 42, and 43, respectively, and light chain variable region
  • the bispecific construct can be a chemical conjugate, which can be made by chemical conjugation of the ILT4 antibody and the second binding agent, e.g., a ligand or an antibody or antigen binding fragment thereof (such as a PD-L1 antibody or antigen binding fragment thereof).
  • the PD-L1 antibody or antigen binding fragment thereof further comprises a human IgG1 constant domain.
  • the ILT4 antibody or antigen binding fragment thereof is linked to the C-terminus of the heavy chain of the PD-L1 antibody or antigen binding fragment thereof.
  • the ILT4 antigen binding fragment thereof is a scFv, e.g., a scFv further comprising disulfide stabilization modifications with Cys substitutions at VH44 and VL100.
  • the ILT4 antibody or antigen binding fragment thereof further comprises a human IgG1 constant domain.
  • the PD-L1 antibody or antigen binding fragment thereof is linked to the C-terminus of the heavy chain of the ILT4 antibody or antigen binding fragment thereof.
  • the PD-L1 antigen binding fragment thereof is a scFv.
  • the bispecific construct comprises a PD-L1 antibody linked to an ILT4 scFv, wherein: (a) the PD-L1 antibody, or antigen binding fragment thereof, comprises heavy chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs: 59, 60, and 61, respectively, and light chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs:62, 63, and 64, respectively; and (b) the ILT4 scFv comprises: (i) heavy chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs:1, 3, and 5, respectively, and light chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs:6, 7, and 8, respectively; or (ii) heavy chain variable region CDR1, CDR2 and CDR3 amino acid sequences as set forth in SEQ ID NOs:11, 13, and
  • the ILT4 scFv of the bispecific (or multispecific) construct further comprises disulfide stabilization modifications with Cys substitutions at VH44 and VL100.
  • the present invention also provides compositions comprising any of the bispecific constructs (multispecific constructs), antibodies, or antigen binding fragments thereof, described herein and a pharmaceutically acceptable carrier, as well as kits comprising any of the bispecific constructs (multispecific constructs), antibodies, or antigen binding fragments thereof, described herein and instructions for use.
  • isolated nucleic acid molecules encoding the antibodies, or antigen binding fragments thereof, and bispecific or multispecific constructs described herein are also provided, as well as expression vectors comprising such nucleic acids and host cells comprising such expression vectors.
  • nucleic acid molecule coding for any of the antibodies, or antigen binding fragments thereof, or bispecific constructs described herein is provided.
  • nucleic acid molecule is in the form of an expression vector.
  • nucleic acid molecule is in the form of an expression vector which expresses the antibody, or antigen binding fragment thereof, or bispecific construct when administered to a subject in vivo.
  • the nucleic acid molecule comprises a nucleotide sequence encoding an antibody heavy and/or light chain variable region, wherein the antibody variable region comprises the amino acid sequence as set forth in SEQ ID NO:9, 10, 19, 20, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, or an amino acid sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to one or more of the aforementioned sequences).
  • the nucleic acid molecule comprises a nucleotide sequence encoding an antibody heavy and/or light chain, wherein the antibody chain comprises the amino acid sequence as set forth in SEQ ID NO:25, 26, 27, 28, or an amino acid sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to one or more of the aforementioned sequences).
  • the nucleic acid molecule comprises a nucleotide sequence encoding heavy and light chain variable regions of an antibody, wherein the heavy and light chain variable regions comprise the amino acid sequences as set forth in SEQ ID NOs:9 and 108 or SEQ ID NOs:19 and 20, respectively, or amino acids sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical the aforementioned sequences).
  • the nucleic acid molecule comprises a nucleotide sequence encoding heavy and light chains of an antibody, wherein the heavy and light chains comprise the amino acid sequences as set forth in SEQ ID NOs:25 and 26 or SEQ ID NOs:27 and 28, respectively, or amino acids sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical the aforementioned sequences).
  • methods for inducing or enhancing an immune response (e.g., against an antigen) in a subject comprising administering to the subject any one of the antibodies, or antigen binding fragments thereof, bispecific constructs, multispecific constructs, or the compositions described herein, in an amount effective to induce or enhance an immune response in the subject (e.g., against an antigen).
  • methods of for treating a condition or disease in a subject e.g., cancer
  • the method comprising administering to the subject any one of the antibodies, or antigen binding fragments thereof, bispecific constructs, multispecific constructs, or the compositions described herein, in an amount effective to treat the condition or disease.
  • methods for treating a tumor e.g., a tumor expressing ILT4, HLA-G, HLA class I, angiopoietin like 2, Nogo, or an ILT4 ligand
  • a tumor e.g., a tumor expressing ILT4, HLA-G, HLA class I, angiopoietin like 2, Nogo, or an ILT4 ligand
  • the method comprising administering to the subject any one of the antibodies, or antigen binding fragments thereof, bispecific constructs, multispecific constructs, or the compositions described herein, in an amount effective to treat the tumor.
  • the subject can be, for example, one who suffers from a condition or disease in which stimulation of an immune response is desired.
  • the condition or disease in which stimulation of an immune response is desired is cancer.
  • the method of inducing or enhancing an immune response (e.g., against an antigen) in a subject can further comprise administering the antigen to the subject.
  • Preferred antigens to be co-administered with the antibodies, or antigen binding fragments thereof, bispecific constructs, multispecific constructs, or the compositions of described herein are tumor antigens.
  • Figures 2A, 2B, and 2C are graphs showing representative traces of the antigen binding kinetic data for antibody 7A3 ( Figure 2A), antibody 7B1 ( Figure 2B), and control antibody ( Figure 2C).
  • Figures 3A and 3B are graphs showing binding of chimeric and humanized monoclonal antibodies to human ILT4 using ELISA; antibody 7A3 ( Figure 3A) and antibody 7B1 ( Figure 3B).
  • Figures 4A and 4B are graphs showing binding to HEK293 cells expressing human ILT4 for antibody 7A3 and its constructs ( Figure 4A) and antibody 7B1 and its constructs ( Figure 4B).
  • Figures 5A and 5B are graphs showing macrophage TNF- ⁇ production for antibody 7A3 and its constructs ( Figure 5A) and antibody 7B1 and its constructs ( Figure 5B).
  • Figures 6A-6F are graphs showing the induction of TNF- ⁇ and MIP1- ⁇ production by humanized antibodies 7A3 VH6-L17 and 7B1 VH10-L21 in macrophages; untreated ( Figures 6A and 6D), with LPS ( Figures 6B and E), and with IFN- ⁇ ( Figures 6C and 6F).
  • Figures 7A, 7B, and 7C are graphs showing relative gene expression in humanized antibodies 7A3 VH6-L17 and 7B1 VH10-L21; Figure 7A (CD86), Figure 7B (CD54), and Figure 7C (iNOS).
  • Figures 8A (antibody 7A3) and 8B (antibody 7B1) are graphs showing cross- reactivity of humanized monoclonal antibodies 7A3 VH6-L17 and 7B1 VH10-L21 to cells expressing ILT family members.
  • Figures 9A (monocytes), 9B (macrophages), and 9C (dendritic cells) are graphs showing binding of humanized monoclonal antibodies 7A3 VH6-L17 and 7B1 VH10-L21 to myeloid cells.
  • Figures 10A (PD-L1 x ILT4) and 10B (PD-1 x ILT4) are schematics showing the depiction of the bispecific constructs.
  • Figure 11 is a table showing the antigen binding kinetics to human ILT4 for the bispecific antibody constructs.
  • Figures 12A (9H9-7A3 HL and 9H9-7A3 LH) and 12B (9H9-7B1 HL and 9H9-7B1 LH) are graphs showing humanized bispecific antibody binding characteristics to human PD- L1 with ELISA.
  • Figures 13A (9H9-7A3 HL and 9H9-7A3 LH) and 13B (9H9-7B1 HL and 9H9-7B1 LH) are graphs showing humanized bispecific antibody binding characteristics to HEK293 cells expressing human PD-L1.
  • Figures 14A (9H9-7A3 HL and 9H9-7A3 LH) and 14B (9H9-7B1 HL and 9H9-7B1 LH) are graphs showing humanized bispecific antibody binding characteristics to HEK293 cells expressing human ILT4.
  • Figures 15A (9H9-7A3 HL and 9H9-7A3 LH) and 15B (9H9-7B1 HL and 9H9-7B1 LH) are graphs showing bifunctional binding characteristics of humanized antibodies to HEK293 cells expressing human ILT4 and PD-L1.
  • Figures 16A (9H9-7A3 HL and 9H9-7A3 LH) and 16B (9H9-7B1 HL and 9H9-7B1 LH) are graphs showing T cell PD-1/PD-L1 blockade by humanized bispecific antibodies.
  • Figures 17A (9H9-7A3 HL and 9H9-7A3 LH) and 17B (9H9-7B1 HL and 9H9-7B1 LH) are graphs showing induction of TNF- ⁇ production by humanized bispecific antibodies in macrophages.
  • Figures 18A (9H9-7A3 HL and 9H9-7A3 LH) and 18B (9H9-7B1 HL and 9H9-7B1 LH) are graphs showing inhibition of HLA-G binding to ILT4 by humanized bispecific antibodies.
  • IV Detailed Description of the Invention
  • immunoglobulin-like transcript 4 or “ILT4” as used herein refers to an inhibitory immune checkpoint receptor and a member of the non-catalytic tyrosine- phosphorylated receptor family.
  • ILT4 is also referred to as leukocyte immunoglobulin like receptor B2 (LILRB2), LIR2, MIR10, and CD85d. ILT4 is expressed on immune cells where it binds to MHC class I molecules on antigen-presenting cells and transduces a negative signal that inhibits stimulation of an immune response, e.g., by controlling inflammatory responses and cytotoxicity to focus the immune response and limit autoreactivity. Multiple isoforms of human ILT4 have been identified. Isoform 1 (Accession No. Q8N423-1; SEQ ID NO: 89) represents the canonical sequence, consisting of 598 amino acid residues.
  • ILT4 antibodies (or antigen binding fragments thereof) of the invention may cross-react with ILT4 from species other than human.
  • the ILT4 antibodies or antigen binding fragments thereof may be specific for human ILT4 and may not exhibit any cross-reactivity with other species.
  • ILT4 or any variants and isoforms thereof may either be isolated from cells or tissues which naturally express them or be recombinantly produced using well-known techniques in the art and/or those described herein.
  • Ligands which bind ILT4 are known in the art and include, among others, HLA-G, HLA class I, angiopoietin like 2, b-amyloid, SEMA4A, CD1c/d, CSPs, and myelin inhibitors such as Nogo66, MAG, OMgp.
  • HLA-G human leukocyte antigen G
  • HLA-G also known as “histocompatibility antigen, class I, G”
  • HLA-G belongs to the HLA nonclassical class I heavy chain paralogues. This class I molecule is a heterodimer consisting of a heavy chain and a light chain (beta-2 microglobulin).
  • the heavy chain is anchored in the membrane. HLA-G is expressed on fetal derived placental cells. The heavy chain is approximately 45 kDa and its gene contains 8 exons.
  • the terms “Programmed cell death 1 ligand 1”, “PD-L1”, “PDCD1 ligand 1”, “Programmed death ligand 1”, “B7 homolog 1”, “B7-H1” and “ILT44” are used interchangeably, and include variants, isoforms, species homologs of human PD-L1, and analogs having at least one common epitope with PD-L1.
  • the complete PD-L1 sequence can be found under GenBank Accession No. NP_001254635 as set forth in SEQ ID NO:176.
  • Programmed death-ligand 1 is a 40kDa type 1 transmembrane protein that has been speculated to play a major role in suppressing the immune system during particular events such as pregnancy, tissue allografts, autoimmune disease, and other disease states such as hepatitis. Normally the immune system reacts to foreign antigens that are associated with exogenous or endogenous danger signals, which triggers a proliferation of antigen-specific CD8+ T cells and/or CD4+ helper cells. The binding of PD-L1 to PD-1 transmits an inhibitory signal that reduces the proliferation of these T cells and can also induce apoptosis, which is further mediated by a lower regulation of the gene Bcl-2.
  • the terms “Programmed Death 1,” “Programmed Cell Death 1,” “Protein PD-1,” “PD-1,” PD1,” “PDCD1,” “hPD-1” and “hPD-I” are used interchangeably, and include variants, isoforms, species homologs of human PD-1, and analogs having at least one common epitope with PD- 1.
  • the complete PD-1 sequence can be found under GenBank Accession No. NP_005009 as set forth in SEQ ID NO:175.
  • PD-L1 is abundant in a variety of human cancers (Dong et al. (2002) Nat. Med. 8:787-9).
  • the term “subject” includes any human or non-human animal.
  • the methods and compositions of the present invention can be used to treat a subject with an immune disorder.
  • non-human animal includes all vertebrates, e.g., mammals and non-mammals, such as non-human primates, sheep, dog, cow, chickens, amphibians, reptiles, etc.
  • antibody as referred to herein refers to a glycoprotein comprising at least two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds, or an antigen binding fragment thereof.
  • Each heavy chain is comprised of a heavy chain variable region (abbreviated herein as VH) and a heavy chain constant region.
  • the heavy chain constant region is comprised of three domains, CH1, CH2 and CH3.
  • Each light chain is comprised of a light chain variable region (abbreviated herein as VL) and a light chain constant region.
  • the light chain constant region is comprised of one domain, CL.
  • the V H and VL regions can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR), interspersed with regions that are more conserved, termed framework regions (FR).
  • CDR complementarity determining regions
  • Each VH and VL is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4.
  • the variable regions of the heavy and light chains contain a binding domain that interacts with an antigen.
  • the constant regions of the antibodies may mediate the binding of the immunoglobulin to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component (Clq) of the classical complement system.
  • antibody fragment refers to one or more fragments or portions of an antibody that retain the ability to specifically bind to an antigen (e.g., human ILT4).
  • fragments are, for example between about 8 and about 1500 amino acids in length, suitably between about 8 and about 745 amino acids in length, suitably about 8 to about 300, for example about 8 to about 200 amino acids, or about 10 to about 50 or 100 amino acids in length. It has been shown that the antigen binding function of an antibody can be performed by fragments of a full- length antibody.
  • binding fragments encompassed within the term “antigen binding fragment” of an antibody include (i) a Fab fragment, a monovalent fragment consisting of the V L , V H , CL and CH1 domains; (ii) a F(ab') 2 fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fd fragment consisting of the VH and CH1 domains; (iv) a Fv fragment consisting of the VL and V H domains of a single arm of an antibody, (v) a dAb fragment (Ward et al., (1989) Nature 341:544-546), which consists of a VH domain; and (vi) an isolated complementarity determining region (CDR) or (vii) a combination of two or more isolated CDRs which may optionally be joined by a synthetic linker.
  • a Fab fragment a monovalent fragment consisting of the V L , V H , CL and CH
  • the two domains of the Fv fragment, VL and VH are coded for by separate genes, they can be joined, using recombinant methods, by a synthetic linker that enables them to be made as a single protein chain in which the V L and V H regions pair to form monovalent molecules (known as single chain Fv (sFv); see e.g., Bird et al. (1988) Science 242:423-426; and Huston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883).
  • single chain Fv single chain Fv
  • Such single chain antibodies are also intended to be encompassed within the term “antigen binding fragment” of an antibody.
  • binding domain refers to the portion of a protein or antibody which comprises the amino acid residues that interact with an antigen. Binding domains include, but are not limited to, antibodies (e.g., full length antibodies), as well as antigen binding fragments thereof. The binding domain confers on the binding agent its specificity and affinity for the antigen.
  • the term also covers any protein having a binding domain which is homologous or largely homologous to an immunoglobulin-binding domain. Such proteins may be derived from natural sources, or partly or wholly synthetically produced.
  • the term “monoclonal antibody,” as used herein, refers to an antibody that displays a single binding specificity and affinity for a particular epitope. Accordingly, the term “human monoclonal antibody” refers to an antibody which displays a single binding specificity and which has variable and optional constant regions derived from human germline immunoglobulin sequences.
  • human monoclonal antibodies are produced by a hybridoma that includes a B cell obtained from a transgenic non-human animal, e.g., a transgenic mouse, having a genome comprising a human heavy chain transgene and a light chain transgene fused to an immortalized cell.
  • recombinant human antibody includes all human antibodies that are prepared, expressed, created or isolated by recombinant means, such as (a) antibodies isolated from an animal (e.g., a mouse) that is transgenic or transchromosomal for human immunoglobulin genes or a hybridoma prepared therefrom, (b) antibodies isolated from a host cell transformed to express the antibody, e.g., from a transfectoma, (c) antibodies isolated from a recombinant, combinatorial human antibody library, and (d) antibodies prepared, expressed, created or isolated by any other means that involve splicing of human immunoglobulin gene sequences to other DNA sequences.
  • variable and constant regions that utilize particular human germline immunoglobulin sequences are encoded by the germline genes, but include subsequent rearrangements and mutations which occur, for example, during antibody maturation.
  • the variable region contains the antigen binding domain, which is encoded by various genes that rearrange to form an antibody specific for a foreign antigen.
  • the variable region can be further modified by multiple single amino acid changes (referred to as somatic mutation or hypermutation) to increase the affinity of the antibody to the foreign antigen.
  • the constant region will change in further response to an antigen (i.e., isotype switch).
  • the rearranged and somatically mutated nucleic acid molecules that encode the light chain and heavy chain immunoglobulin polypeptides in response to an antigen may not have sequence identity with the original nucleic acid molecules, but instead will be substantially identical or similar (i.e., have at least 80% identity).
  • the term “human antibody” includes antibodies having variable and constant regions (if present) of human germline immunoglobulin sequences. Human antibodies of the invention can include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo) (see, Lonberg, N. et al.
  • human antibody does not include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences (i.e., chimeric and humanized antibodies).
  • a “humanized” antibody refers to an antibody in which some, most, or all of the amino acids outside the CDR domains of a non-human antibody are replaced with corresponding amino acids derived from human immunoglobulins. In one embodiment of a humanized form of an antibody, some, most or all of the amino acids outside the CDR domains have been replaced with amino acids from human immunoglobulins, whereas some, most or all amino acids within one or more CDR regions are unchanged. Small additions, deletions, insertions, substitutions or modifications of amino acids are permissible as long as they do not abrogate the ability of the antibody to bind to a particular antigen.
  • a "humanized” antibody retains an antigenic specificity similar to that of the original antibody.
  • an “isolated antibody,” as used herein, is intended to refer to an antibody which is substantially free of other antibodies having different antigenic specificities (e.g., an isolated antibody that specifically binds to human ILT4 is substantially free of antibodies that specifically bind antigens other than human ILT4; an isolated antibody that specifically binds to human PD-L1 is substantially free of antibodies that specifically bind antigens other than human PD-L1).
  • An isolated antibody that specifically binds to an epitope may, however, have cross-reactivity to the same antigen from different species.
  • an isolated antibody is typically substantially free of other cellular material and/or chemicals.
  • epitopes refers to a site on an antigen to which an immunoglobulin or antibody specifically binds.
  • Epitopes can be formed both from contiguous amino acids or noncontiguous amino acids juxtaposed by tertiary folding of a protein. Epitopes formed from contiguous amino acids are typically retained on exposure to denaturing solvents, whereas epitopes formed by tertiary folding are typically lost on treatment with denaturing solvents.
  • An epitope typically includes at least 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 amino acids in a unique spatial conformation.
  • epitope mapping Methods for determining what epitopes are bound by a given antibody (i.e., epitope mapping) are well known in the art and include, for example, immunoblotting and immunoprecipitation assays, wherein overlapping or contiguous peptides from the antigen (e.g., ILT4 or PD-L1) are tested for reactivity with the given antibody (e.g., an ILT4 or PD-L1 antibody.
  • Methods of determining spatial conformation of epitopes include techniques in the art and those described herein, for example, x-ray crystallography and 2-dimensional nuclear magnetic resonance (see, e.g., Epitope Mapping Protocols in Methods in Molecular Biology, Vol.66, G. E. Morris, Ed. (1996)).
  • antibody that binds the same epitope is intended to encompass antibodies that interact with, i.e., bind to, the same structural region on human ILT4 as a reference ILT4 antibody.
  • the “same epitope” to which the antibodies bind may be a linear epitope or a conformational epitope formed by tertiary folding of the antigen.
  • the term “competing antibody” refers to an antibody that competes for binding to human ILT4 with a reference ILT4 antibody, i.e., competitively inhibits binding of the reference ILT4 antibody to ILT4.
  • a “competing antibody” may bind the same epitope on ILT4 as the reference ILT4 antibody, may bind to an overlapping epitope or may sterically hinder the binding of the reference ILT4 antibody to ILT4.
  • Antibodies that recognize the same epitope or compete for binding can be identified using routine techniques. Such techniques include, for example, an immunoassay, which shows the ability of one antibody to block the binding of another antibody to a target antigen, i.e., a competitive binding assay.
  • Competitive binding is determined in an assay in which the immunoglobulin under test inhibits specific binding of a reference antibody to a common antigen, such as ILT4.
  • RIA solid phase direct or indirect radioimmunoassay
  • EIA solid phase direct or indirect enzyme immunoassay
  • sandwich competition assay see Stahli et al., Methods in Enzymology 9:242 (1983)
  • solid phase direct biotin-avidin EIA see Kirkland et al., J. Immunol.137:3614 (1986)
  • solid phase direct labeled assay solid phase direct labeled sandwich assay
  • solid phase direct labeled sandwich assay see Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Press (1988)
  • solid phase direct label RIA using I-125 label see Morel et al., Mol.
  • a competing antibody when it is present in excess, it will inhibit specific binding of a reference antibody to a common antigen by at least 50-55%, 55-60%, 60-65%, 65-70% 70-75% or more.
  • Other techniques include, for example, epitope mapping methods, such as, x-ray analyses of crystals of antigen:antibody complexes which provides atomic resolution of the epitope.
  • Other methods monitor the binding of the antibody to antigen fragments or mutated variations of the antigen where loss of binding due to a modification of an amino acid residue within the antigen sequence is often considered an indication of an epitope component.
  • computational combinatorial methods for epitope mapping can also be used.
  • the antibody binds with an equilibrium dissociation constant (K D ) of approximately less than 10 -7 M, such as approximately less than 10 -8 M, 10 -9 M or 10 -10 M or even lower when determined by surface plasmon resonance (SPR) technology in a BIACORE 2000 instrument (e.g., using recombinant human ILT4 as the analyte and the antibody as the ligand) and binds to the predetermined antigen with an affinity that is at least two-fold greater than its affinity for binding to a non-specific antigen (e.g., BSA, casein) other than the predetermined antigen or a closely-related antigen.
  • K D equilibrium dissociation constant
  • an antibody recognizing an antigen and “an antibody specific for an antigen” are used interchangeably herein with the term “an antibody which binds specifically to an antigen.”
  • KD is intended to refer to the dissociation equilibrium constant of a particular antibody-antigen interaction.
  • the human antibodies of the invention bind to ILT4 with a dissociation equilibrium constant (K D ) of approximately 10 -8 M or less, such as less than 10 -9 M or 10 -10 M or even lower when determined by surface plasmon resonance (SPR) technology in a BIACORE 2000 instrument (e.g., using recombinant human ILT4 as the analyte and the antibody as the ligand).
  • SPR surface plasmon resonance
  • the term “kd” as used herein, is intended to refer to the off rate constant for the dissociation of an antibody from the antibody/antigen complex.
  • the term “ka” as used herein, is intended to refer to the on rate constant for the association of an antibody with the antigen.
  • the term “EC50,” as used herein, refers to the concentration of an antibody or an antigen binding fragment thereof, which induces a response, either in an in vitro or an in vivo assay, which is 50% of the maximal response, i.e., halfway between the maximal response and the baseline.
  • isotype refers to the antibody class (e.g., IgM or IgGl) that is encoded by heavy chain constant region genes.
  • a human monoclonal antibody of the invention is of the IgG1 isotype. In another embodiment, a human monoclonal antibody of the invention is of the IgG2 isotype.
  • the terms “inhibits” or “blocks” are used interchangeably and encompass both partial and complete inhibition/blocking. The inhibition/blocking preferably reduces or alters the normal level or type of activity that occurs when binding occurs without inhibition or blocking.
  • Inhibition and blocking are also intended to include any measurable decrease in the binding affinity of HLA-G when in contact with an ILT4 antibody as compared to HLA-G not in contact with an ILT4 antibody, e.g., inhibits binding of HLA-G by at least about 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% , 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100%.
  • the ILT4 antibody inhibits binding of HLA-G by at least about 70%.
  • the ILT4 antibody inhibits binding of HLA-G by at least 80%.
  • Inhibition and blocking are also intended to include any measurable decrease in the binding affinity of PD1 when in contact with an PD-L1 antibody as compared to PD1 not in contact with an PD-L1 antibody, e.g., inhibits binding of PD1 by at least about 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% , 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100%.
  • the PD-L1 antibody inhibits binding of PD1 by at least about 70%.
  • the PD-L1 antibody inhibits binding of PD1 by at least 80%.
  • cross-reacts refers to the ability of an ILT4 antibody or antigen binding fragment thereof or a PD-L1 antibody or antigen binding fragment thereof of the invention to bind to ILT4 or PD-L1, respectively, from a different species.
  • a ILT4 antibody or antigen binding fragment thereof of the invention that binds human ILT4 may also bind another species of ILT4.
  • an PD-L1 antibody or antigen binding fragment thereof of the invention that binds human PD-L1 may also bind another species of PD-L1.
  • cross-reactivity is measured by detecting a specific reactivity with purified antigen in binding assays (e.g., SPR, ELISA) or binding to, or otherwise functionally interacting with, cells physiologically expressing ILT4.
  • binding assays e.g., SPR, ELISA
  • Methods for determining cross- reactivity include standard binding assays as described herein, for example, by Biacore TM surface plasmon resonance (SPR) analysis using a Biacore TM 2000 SPR instrument (Biacore AB, Uppsala, Sweden), or flow cytometric techniques.
  • SPR Biacore TM surface plasmon resonance
  • nucleic acid molecule is intended to include DNA molecules and RNA molecules.
  • a nucleic acid molecule may be single-stranded or double- stranded, but preferably is double-stranded DNA.
  • isolated nucleic acid molecule as used herein in reference to nucleic acids encoding binding domains, antibodies, or antibody portions (e.g., V H , V L , CDR3) that bind to ILT4 and/or PD-L1, is intended to refer to a nucleic acid molecule in which the nucleotide sequences encoding the antibodies, or antibody portions are free of other nucleotide sequences encoding the antibodies, or antibody portions that bind antigens other than ILT4 and/or PD-L1, which other sequences may naturally flank the nucleic acid in human genomic DNA.
  • the nucleic acids may be present in whole cells, in a cell lysate, or in a partially purified or substantially pure form.
  • a nucleic acid is “isolated” or “rendered substantially pure” when purified away from other cellular components or other contaminants, e.g., other cellular nucleic acids or proteins, by standard techniques, including alkaline/SDS treatment, CsCl banding, column chromatography, agarose gel electrophoresis and others well known in the art. See, F. Ausubel, et al., ed. Current Protocols in Molecular Biology, Greene Publishing and Wiley Interscience, New York (1987).
  • the nucleic acid molecules of the present invention while often in a native sequence (except for modified restriction sites and the like), from either cDNA, genomic or mixtures thereof may be mutated, in accordance with standard techniques to provide gene sequences.
  • coding sequences these mutations, may affect amino acid sequence as desired.
  • DNA sequences substantially identical to or derived from native V, D, J, constant, switches and other such sequences described herein are contemplated (where "derived” indicates that a sequence is identical or modified from another sequence).
  • a nucleic acid is “operably linked” or “operatively linked” when it is placed into a functional relationship with another nucleic acid sequence.
  • a promoter or enhancer is operably linked to a coding sequence if it affects the transcription of the sequence.
  • operably linked means that the DNA sequences being linked are contiguous and, where necessary to join two protein coding regions, contiguous and in reading frame.
  • operably linked indicates that the sequences are capable of effecting switch recombination.
  • the present invention also encompasses “conservative sequence modifications” of any of the sequences described herein, i.e., nucleotide and amino acid sequence modifications which do not abrogate the binding of the VH and VL sequences encoded by the nucleotide sequence or containing the amino acid sequence, to the antigen.
  • conservative sequence modifications include conservative nucleotide and amino acid substitutions, as well as, nucleotide and amino acid additions and deletions.
  • modifications can be introduced into the sequences by standard techniques known in the art, such as site-directed mutagenesis and PCR-mediated mutagenesis.
  • Conservative amino acid substitutions include ones in which the amino acid residue is replaced with an amino acid residue having a similar side chain.
  • Families of amino acid residues having similar side chains have been defined in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, tryptophan), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine).
  • basic side chains
  • a predicted nonessential amino acid residue in an ILT4 antibody is preferably replaced with another amino acid residue from the same side chain family.
  • Methods of identifying nucleotide and amino acid conservative substitutions which do not eliminate antigen binding are well-known in the art (see, e.g., Brummell et al., Biochem.32:1180-1187 (1993); Kobayashi et al. Protein Eng. 12(10):879-884 (1999); and Burks et al. Proc. Natl. Acad. Sci. USA 94:412-417 (1997)).
  • conservative amino acid sequence modifications refer to at most 1, 2, 3, 4 or 5 conservative amino acid substitutions to the CDR sequences described herein.
  • each such CDR may contain up to 5 conservative amino acid substitutions, e.g., up to (i.e., not more than) 4 conservative amino acid substitutions, e.g.,up to (i.e., not more than) 3 conservative amino acid substitutions, e.g., up to (i.e., not more than) 2 conservative amino acid substitutions, or no more than 1 conservative amino acid substitution.
  • mutations can be introduced randomly along all or part of an ILT4 or PD-L1 or PD-1 antibody or antigen binding fragment thereof coding sequence, such as by saturation mutagenesis, and the resulting modified ILT4 or PD-L1 or PD-1 antibodies can be screened for binding activity.
  • nucleic acids For nucleic acids, the term “substantial homology” indicates that two nucleic acids, or designated sequences thereof, when optimally aligned and compared, are identical, with appropriate nucleotide insertions or deletions, in at least about 80% of the nucleotides, usually at least about 90% to 95%, and more preferably at least about 98% to 99.5% of the nucleotides. Alternatively, substantial homology exists when the segments will hybridize under selective hybridization conditions, to the complement of the strand.
  • the term “substantial homology” indicates that two amino acid sequences, or designated sequences thereof, when optimally aligned and compared, are identical, with appropriate amino acid insertions or deletions, in at least about 80% of the amino acids, usually at least about 90% to 95%, and more preferably at least about 98% to 99% or 99.5% of the amino acids.
  • the comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm, as described in the non-limiting examples below.
  • the percent identity between two nucleotide sequences can be determined using the GAP program in the GCG software package (available at http://www.gcg.com), using a NWSgapdna.CMP matrix and a gap weight of 40, 50, 60, 70, or 80 and a length weight of 1, 2, 3, 4, 5, or 6.
  • the percent identity between two nucleotide or amino acid sequences can also be determined using the algorithm of E. Meyers and W.
  • the percent identity between two amino acid sequences can be determined using the Needleman and Wunsch (J. Mol. Biol. (48):444-453 (1970)) algorithm which has been incorporated into the GAP program in the GCG software package (available at http://www.gcg.com), using either a Blossum 62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6.
  • the nucleic acid and protein sequences of the present invention can further be used as a “query sequence” to perform a search against public databases to, for example, identify related sequences.
  • Such searches can be performed using the NBLAST and XBLAST programs (version 2.0) of Altschul, et al. (1990) J. Mol. Biol.215:403-10.
  • Gapped BLAST can be utilized as described in Altschul et al., (1997) Nucleic Acids Res.25(17):3389-3402.
  • the default parameters of the respective programs e.g., XBLAST and NBLAST
  • ILT4 Antibodies and Antigen Binding Fragments Thereof Provided herein are novel ILT4 antibodies (or antigen binding fragments thereof), e.g., humanized antibodies, which are characterized by particular functional features or properties.
  • antibodies (or fragments) of the present invention exhibit one or more of the following properties: a. blocking ILT4 ligand (e.g., HLA-G ligand) binding to human ILT4; b. enhancing or increasing cytokine or chemokine release by human macrophages; c. potentiating the activation effects of LPS and IFN ⁇ on macrophages; d. promoting M1 macrophage polarization; e. binding to human ILT4 with an equilibrium dissociation constant Kd of 10 -9 M or less, or alternatively, an equilibrium association constant Ka of 10 +9 M -1 or greater; f. lack of cross-reactivity with other ILT family members; g.
  • ILT4 ligand e.g., HLA-G ligand
  • an exemplary ILT4 antibody is antibody 7A3 as described herein.
  • the ILT4 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 7A3.
  • the antibody or antigen binding fragment comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 7A3 having the sequence set forth in SEQ ID NO:9, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 7A3 having the sequence set forth in SEQ ID NO:10.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:1, 3, and 5, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:6, 7, and 8, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:2, 4, and 5, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:6, 7, and 8, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:9.
  • the antibody or antigen binding fragment comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:97, 98, or 99.
  • the antibody or antigen binding fragment thereof comprises a light chain variable region having the amino acid sequence set forth in SEQ ID NO:10.
  • the antibody or antigen binding fragment comprises a light chain variable region having the amino acid sequence set forth in SEQ ID NO:100, 101, or 102.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein: (a) the heavy chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 9, 97, 98, and 99, and (b) the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NOs:10, 100, 101, and 102.
  • the antibody or antigen binding fragment comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:9 and 10.
  • Another exemplary ILT4 antibody is antibody 7B1 as described herein.
  • the ILT4 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 7B1.
  • the antibody or antigen binding fragment comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 7B1 having the sequence set forth in SEQ ID NO:19, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 7B1 having the sequence set forth in SEQ ID NO:20.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:11, 13, and 15, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:16, 17, and 18, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:12, 14, and 15, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:16, 17, and 18, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:19.
  • the antibody or antigen binding fragment comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:103, 104, or 105.
  • the antibody or antigen binding fragment thereof comprises a light chain variable region having the amino acid sequence set forth in SEQ ID NO:20.
  • the antibody or antigen binding fragment comprises a light chain variable region having the amino acid sequence set forth in SEQ ID NO:106, 107, or 108.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein: (a) the heavy chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 19, 103, 104, and 105, and (b) the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NOs:20, 106, 107, and 108.
  • the antibody or antigen binding fragment comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:19 and 20.
  • the antibody sequences can also be consensus sequences of several antibodies.
  • the ILT4 antibody or antigen binding fragment comprises a heavy chain variable region CDR1 comprising an amino acid sequence selected from the consensus sequence: G Y T (I,M) H (SEQ ID NO: 21).
  • the ILT4 antibody or antigen binding fragment comprises a heavy chain variable region CDR2 comprising SEQ ID NO:3.
  • the ILT4 antibody or antigen binding fragment comprises a heavy chain variable region CDR3 comprising an amino acid sequence selected from the consensus sequence: E R P G G S Q F I Y Y Y (P,A) (M,L) D Y (SEQ ID NO:22).
  • the ILT4 antigen binding fragment comprises a light chain variable region CDR1 comprising an amino acid sequence selected from the consensus sequence: R A S (A,E) N I Y S Y L A (SEQ ID NO: 23).
  • the ILT4 antibody or antigen binding fragment comprises a light chain variable region CDR2 comprising an amino acid sequence selected from the consensus sequence: N A (I,D) T L A E (SEQ ID NO: 24).
  • the ILT4 antibody or antigen binding fragment comprises a light chain variable region CDR3 comprising SEQ ID NO:8.
  • VH and VL sequences described herein can be “mixed and matched” to create various ILT4 antibodies or antigen binding fragments thereof.
  • the binding of such “mixed and matched” antibodies to human ILT4 can be tested using the binding assays known in the art and described in the Examples (e.g., ELISAs).
  • ILT4 antibodies and antigen binding fragments thereof of the present invention include combinations of heavy and light chain variable region sequences as set forth in Table 1.
  • VH and VL Sequence Combinations (SEQ ID NOs) Sequences substantially identical to the ILT4 antibodies and antigen binding fragments thereof described herein (e.g., sequences at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences) are also provided.
  • the ILT4 antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:9, 97, 98, 99, 19, 103, 104, 105, or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95% 96%, 97%, 98%, or 99% identical to the aforementioned sequences).
  • the ILT4 antibody or antigen binding fragment thereof comprises a light chain variable region comprising SEQ ID NO:10, 100, 101, 102, 20, 106, 107, 108, or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the ILT4 antibody (or antigen binding fragment thereof) comprises a (a) heavy chain variable region comprising SEQ ID NO:9, 97, 98, 99, 19, 103, 104, 105, or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences) and (b) light chain variable region comprising SEQ ID NO: 10, 100, 101, 102, 20, 106, 107, or 108, or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequence
  • the ILT4 antibody or antigen binding fragment thereof comprises SEQ ID NO: 9, or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical thereto) and SEQ ID NO:19, or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical thereto).
  • the ILT4 antibody or antigen binding fragment thereof comprises SEQ ID NO:10, or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical thereto) and SEQ ID NO:20, or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical thereto).
  • SEQ ID NO:10 or a sequence at least 80% identical thereto (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,
  • ILT4 antibodies and antigen binding fragments thereof that compete for binding with any of the ILT4 antibody or fragments thereof described herein, or that bind the same epitope as any of the ILT4 antibody or fragments thereof described herein.
  • the ILT4 antibody or antigen binding fragment thereof competes for binding to ILT4 with antibody 7A3 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 7A3).
  • the ILT4 antibody or antigen binding fragment thereof competes for binding to ILT4 with antibody 7B1 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 7B1).
  • the ILT4 antibody or antigen binding fragment thereof binds to the same epitope on ILT4 as antibody 7A3 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 7A3). In another embodiment, the ILT4 antibody or antigen binding fragment thereof binds to the same epitope on ILT4 as antibody 7B1 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 7B1).
  • the ILT4 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:1, 3, and 5, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:6, 7, and 8, respectively.
  • the ILT4 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:2, 4, and 5, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:6, 7, and 8, respectively.
  • the ILT4 antibody, or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:9 and a light chain variable region comprising SEQ ID NO:19 or sequences at least 80% identical to te aforementioned sequences (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical).
  • the ILT4 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:11, 13, and 15, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:16, 17, and 18, respectively.
  • the ILT4 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:12, 14, and 15, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:16, 17, and 18, respectively.
  • the ILT4 antibody, or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:10 and a light chain variable region comprising SEQ ID NO:20 or sequences at least 80% identical to the aforementioned sequences (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical).
  • a heavy chain variable region comprising SEQ ID NO:10
  • a light chain variable region comprising SEQ ID NO:20 or sequences at least 80% identical to the aforementioned sequences (e.g., at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical).
  • PD-L1 Antibodies and Antigen Binding Fragments Thereof Provided herein are PD-L1 antibodies and antigen binding fragments thereof for use with the ILT4 antibodies or antigen binding fragments of the present invention, e.g., in bispecific and multispecific constructs, as well as methods of treatment.
  • An exemplary PD-L1 antibody is antibody 7H7 as described herein.
  • the PD-L1 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 7H7.
  • the antibody or antigen binding fragment thereof comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 7H7 having the sequence set forth in SEQ ID NO:77, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 7H7 having the sequence set forth in SEQ ID NO:78.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:29, 30, and 31, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:32, 33, and 34, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:77. In another embodiment, the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:77. In another embodiment, the antibody or antigen binding fragment thereof comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:77 and SEQ ID NO:78, respectively.
  • Another exemplary PD-L1 antibody is antibody 1B3 as described herein. In one embodiment, the PD-L1 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 1B3.
  • the antibody or antigen binding fragment thereof comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 1B3 having the sequence set forth in SEQ ID NO:79, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 1B3 having the sequence set forth in SEQ ID NO:80.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:35, 36, and 37, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:38, 39, and 40, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequences set forth in SEQ ID NO:79. In another embodiment, the antibody or antigen binding fragment thereof comprises a light chain variable region having the amino acid sequences set forth in SEQ ID NO:80. In another embodiment, the antibody or antigen binding fragment thereof comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:79 and SEQ ID NO:80, respectively.
  • Another exemplary PD-L1 antibody is antibody 3B6 as described herein. In one embodiment, the PD-L1 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 3B6.
  • the antibody or antigen binding fragment thereof comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 3B6 having the sequence set forth in SEQ ID NO:81, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 3B6 having the sequence set forth in SEQ ID NO:82.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:41, 42, and 43, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:44, 45, and 46, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:81. In another embodiment, the antibody or antigen binding fragment thereof comprises a light chain variable region having the amino acid sequence set forth in SEQ ID NO:82. In another embodiment, the antibody or antigen binding fragment n thereof comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:81 and SEQ ID NO:82, respectively.
  • Another exemplary PD-L1 antibody is antibody 8B1 as described herein. In one embodiment, the PD-L1 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 8B1.
  • the antibody or antigen binding fragment thereof comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 8B1 having the sequence set forth in SEQ ID NO:83, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 8B1 having the sequence set forth in SEQ ID NO:84.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:47, 48, and 49, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:50, 51, and 52, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequences set forth in SEQ ID NO:83. In another embodiment, the antibody or antigen binding fragment thereof comprises a light chain variable region having the amino acid sequences set forth in SEQ ID NO:84. In another embodiment, the antibody or antigen binding fragment thereof comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:83 and SEQ ID NO:84, respectively.
  • Another exemplary PD-L1 antibody is antibody 4A3 as described herein. In one embodiment, the PD-L1 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 4A3.
  • the antibody or antigen binding fragment thereof comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 4A3 having the sequence set forth in SEQ ID NO:85, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 4A3 having the sequence set forth in SEQ ID NO:86.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:53, 54, and 55, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:56, 57, and 58, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:85. In another embodiment, the antibody or antigen binding fragment thereof comprises a light chain variable region having the amino acid sequence set forth in SEQ ID NO:86. In another embodiment, the antibody or antigen binding fragment thereof comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:85 and SEQ ID NO:86, respectively.
  • Another exemplary PD-L1 antibody is antibody 9H9 as described herein. In one embodiment, the PD-L1 antibody or antigen binding fragment thereof comprises the heavy and light chain CDRs or variable regions of antibody 9H9.
  • the antibody or antigen binding fragment thereof comprises the CDR1, CDR2, and CDR3 domains of the heavy chain variable region of antibody 9H9 having the sequence set forth in SEQ ID NO:87, and the CDR1, CDR2 and CDR3 domains of the light chain variable region of antibody 9H9 having the sequence set forth in SEQ ID NO:88.
  • the antibody or antigen binding fragment thereof comprises heavy chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:59, 60, and 61, respectively, or conservative sequence modifications thereof, and light chain CDR1, CDR2 and CDR3 domains having the sequences set forth in SEQ ID NOs:62, 63, and 64, respectively, or conservative sequence modifications thereof.
  • the antibody or antigen binding fragment thereof comprises a heavy chain variable region having the amino acid sequence set forth in SEQ ID NO:87. In another embodiment, the antibody or antigen binding fragment thereof comprises a light chain variable region having the amino acid sequence set forth in SEQ ID NO:88. In another embodiment, the antibody or antigen binding fragment thereof comprises heavy and light chain variable regions having the amino acid sequences set forth in SEQ ID NO:87 and SEQ ID NO:88, respectively.
  • the antibody sequences can also be consensus sequences of several antibodies.
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region CDR1 comprising an amino acid sequence selected from the consensus sequence: (T,S)(S,Y,H)WMS (SEQ ID NO:167).
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region CDR2 comprising SEQ ID NO:168. In another embodiment, the PD-L1 antigen binding fragment comprises a heavy chain variable region CDR3 comprising SEQ ID NO:169. In another embodiment, the PD- L1 antigen binding fragment comprises a light chain variable region CDR1 comprising SEQ ID NO:170. In another embodiment, the PD-L1 antigen binding fragment comprises a light chain variable region CDR2 comprising SEQ ID NO:171. In another embodiment, the PD- L1 antigen binding fragment comprises a light chain variable region CDR3 comprising SEQ ID NO:172.
  • Sequences substantially identical to the PD-L1 antibodies and antigen binding fragments thereof described herein are also encompassed by the invention.
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region comprising SEQ ID NO:77, SEQ ID NO:79, SEQ ID NO:81, SEQ ID NO:83, SEQ ID NO:85, SEQ ID NO:87, or a sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antigen binding fragment comprises a light chain variable region comprising SEQ ID NO:78, SEQ ID NO:80, SEQ ID NO:82, SEQ ID NO:84, SEQ ID NO:86, SEQ ID NO:88 or a sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region comprising SEQ ID NO:77 and a light chain variable region comprising SEQ ID NO:78 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region comprising SEQ ID NO:79 and a light chain variable region comprising SEQ ID NO:80 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region comprising SEQ ID NO:81 and a light chain variable region comprising SEQ ID NO:82 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region comprising SEQ ID NO:83 and a light chain variable region comprising SEQ ID NO:84 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region comprising SEQ ID NO:85 and a light chain variable region comprising SEQ ID NO:86 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antigen binding fragment comprises a heavy chain variable region comprising SEQ ID NO:87 and a light chain variable region comprising SEQ ID NO:88 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • Other exemplary antibodies include PD-L1 antibodies and antigen binding fragments thereof that compete for binding with any of the PD-L1 antibodies or antigen binding fragments thereof as described herein, or that bind the same epitope as any of the PD-L1 antibodies or antigen binding fragments thereof as described herein.
  • the PD-L1 antibody or antigen binding fragment thereof competes for binding to PD-L1 with antibody 7H7 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 7H7). In another embodiment, the PD-L1 antibody or antigen binding fragment thereof binds to the same epitope on PD-L1 as antibody 7H7 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 7H7).
  • the PD-L1 antibody or antigen binding fragment thereof competes for binding to PD-L1 with antibody 1B3 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 1B3). In another embodiment, the PD-L1 antibody or antigen binding fragment thereof binds to the same epitope on PD-L1 as antibody 1B3 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 1B3).
  • the PD-L1 antibody or antigen binding fragment thereof competes for binding to PD-L1 with antibody 3B6 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 3B6).
  • the PD-L1 antibody or antigen binding fragment thereof binds to the same epitope on PD-L1 as antibody 3B6 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 3B6).
  • the PD-L1 antibody or antigen binding fragment thereof competes for binding to PD-L1 with antibody 8B1 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 8B1). In another embodiment, the PD-L1 antibody or antigen binding fragment thereof binds to the same epitope on PD-L1 as antibody 8B1 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 8B1).
  • the PD-L1 antibody or antigen binding fragment thereof competes for binding to PD-L1 with antibody 4A3 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 4A3).
  • the PD-L1 antibody or antigen binding fragment thereof binds to the same epitope on PD-L1 as antibody 4A3 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 4A3).
  • the PD-L1 antibody or antigen binding fragment thereof competes for binding to PD-L1 with antibody 9H9 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 9H9).
  • the PD-L1 antibody or antigen binding fragment thereof binds to the same epitope on PD-L1 as antibody 9H9 (or an antibody having the heavy and light chain CDRs and/or heavy and light chain variable region sequences corresponding to antibody 9H9).
  • the PD-L1 antigen binding fragment is an PD-L1 antibody, or antigen binding fragment thereof.
  • the PD-L1 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:29, 30, and 31, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:32, 33, and 34, respectively.
  • the PD-L1 antibody, or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:77 and a light chain variable region comprising SEQ ID NO:78 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:35, 36, and 37, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:38, 39, and 40, respectively.
  • the PD-L1 antibody, or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:79 and a light chain variable region comprising SEQ ID NO:80 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:41, 42, and 43, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:44, 45, and 46, respectively.
  • the PD-L1 antibody, or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:81 and a light chain variable region comprising SEQ ID NO:82 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:47, 48, and 49, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:50, 51, and 52, respectively.
  • the PD-L1 antibody, or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:83 and a light chain variable region comprising SEQ ID NO:84 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:53, 54, and 55, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:56, 57, and 58, respectively.
  • the PD-L1 antibody, or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:85 and a light chain variable region comprising SEQ ID NO:86 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antibody, or antigen binding fragment thereof comprises heavy chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:59, 60, and 61, respectively, and light chain variable region CDR1, CDR2 and CDR3 as set forth in SEQ ID NOs:62, 63, and 64, respectively.
  • the PD-L1 antibody, or antigen binding fragment thereof comprises a heavy chain variable region comprising SEQ ID NO:87 and a light chain variable region comprising SEQ ID NO:88 or sequences at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the PD-L1 antibody, or antigen binding fragment thereof has one or more of the following functional features: (a) blocks binding of PD1 to PD-L1 (e.g., partially or completely), (b) induces NFAT pathway activation, and/or (c) induces a mixed lymphocyte reaction. D.
  • binding agents for use with the ILT4 antibodies or antigen binding fragments of the present invention include, e.g., binding agents which bind to an immune checkpoint molecule (such as PD-1, PD-L1 CTLA-4, LAG-3, TIGIT, TIM-3, VISTA, AXL, ILT2, or ILT3), an immune costimulatory molecule (such as CD27, CD40, 4-1BB, OX40, or GITR), or a tumor antigen (such as HER2, EGFR, ErB3, or CD24).
  • an immune checkpoint molecule such as PD-1, PD-L1 CTLA-4, LAG-3, TIGIT, TIM-3, VISTA, AXL, ILT2, or ILT3
  • an immune costimulatory molecule such as CD27, CD40, 4-1BB, OX40, or GITR
  • a tumor antigen such as HER2, EGFR, ErB3, or CD24.
  • Exemplary binding agents include antibodies or antigen binding fragments thereof which bind to human PD-1, e.g., a PD-1 antagonist.
  • An exemplary PD-1 antibody is nivolumab (referred to as 5C4 in WO 2006/121168; also known as BMS-936558, MDX-1106 or ONO-4538).
  • Particular exemplary binding agents include PD-L1 and PD-1 antibodies (or antigen binding fragments thereof) such as durvalumab, pembrolizumab (Keytruda®), cemiplimab (Libtaylo®), avelumab (Bavencio®), durvalumab (Imfinzi®), and atezolizumab (Tecentriq®).
  • bispecific and Multispecific Constructs comprising an ILT4 antibody or antigen binding fragment thereof linked to a second binding agent, e.g., a second binding agent that binds to an immune checkpoint molecule (such as PD-1, PD-L1 CTLA-4, LAG-3 TIGIT, TIM-3, VISTA, AXL, ILT2, or ILT3), an immune costimulatory molecule (such as CD27, CD40, 4-1BB, OX40, or GITR), or a tumor antigen (such as HER2, EGFR, ErB3, or CD24), for example, a bispecific construct comprising an ILT4 antibody (or antigen binding fragment thereof) linked to a PD-L1 or PD-1 antibody (or antigen binding fragment thereof).
  • a second binding agent that binds to an immune checkpoint molecule (such as PD-1, PD-L1 CTLA-4, LAG-3 TIGIT, TIM-3, VISTA, AXL, ILT2, or ILT3), an
  • bispecific constructs linked to one or more additional binding agent to form multispecific constructs are described.
  • a “bispecific” or “bifunctional” construct is an artificial hybrid having two different binding domain (e.g., heavy/light chain) pairs and two different binding sites.
  • Bispecific constructs can be produced by a variety of methods including fusion of hybridomas or linking of Fab' fragments. See, e.g., Songsivilai & Lachmann, Clin. Exp. Immunol.79:315-321 (1990); Kostelny et al., J. Immunol.
  • the term “linked” refers to the association of two or more molecules. The linkage can be covalent or non-covalent.
  • the linkage also can be genetic (i.e., recombinantly fused). Such linkages can be achieved using a wide variety of art recognized techniques, such as chemical conjugation and recombinant protein production.
  • suitable reagents and methods are known in the art for coupling two or more moieties, in particular two or more antibodies, or fragments thereof, together.
  • a variety of coupling or crosslinking agents are commercially available and can be used to conjugate the ILT4 antibody or antigen binding fragment thereof and PD-L1 or PD-1 antibody or antigen binding fragment thereof.
  • Non-limiting examples include Sulfo-SMCC, protein A, carboiimide, dimaleimide, dithio-bis-nitrobenzoic acid (DTNB), and N- succinimidyl-3-(2-pyridyldithio) propionate (SPDP).
  • Sulfo-SMCC, SPDP and DTNB are preferred agents, with Sulfo-SMCC being particularly preferred.
  • Other suitable procedures for crosslinking components (e.g., antibodies or antigen binding fragments thereof) with cross-linking agents are known in the art. See e.g., Karpovsky, B. et al., (1984) J. Exp. Med. 160:1686; Liu, M. A. et al., (1985) Proc. Natl.
  • nucleic acid molecules encoding the ILT4 antibody or antigen binding fragment thereof can be inserted into an appropriate expression vector using standard recombinant DNA techniques.
  • a nucleic acid molecule(s) encoding the PD-L1 or PD-1 antibody or antigen binding fragment thereof also can be inserted into the same expression vector, such that it is operatively linked (e.g., in-frame cloning) to the ILT4 antibody or antigen binding fragment thereof, thereby resulting in an expression vector that encodes a fusion protein that is the bispecific construct.
  • the PD-L1 or PD-1 antibody or antigen binding fragment thereof is operatively linked to the C-terminal region of the heavy chain of the ILT4 antibody or antigen binding fragment thereof.
  • Other suitable expression vectors and cloning strategies for preparing the bispecific constructs described herein are known in the art.
  • the coding regions of the antibodies or antigen binding fragments thereof are combined with cloned promoter, leader sequence, translation initiation, leader sequence, constant region, 3’ untranslated, polyadenylation, and transcription termination, sequences to form expression vector constructs.
  • These constructs can be used to express, for example, full length human IgG 1 ⁇ or IgG4 ⁇ antibodies.
  • Fully human, humanized and chimeric antibodies used in the bispecific constructs described herein also include IgG2, IgG3, IgE, IgA, IgM, and IgD antibodies. Similar plasmids can be constructed for expression of other heavy chain isotypes, or for expression of antibodies comprising lambda light chains.
  • the bispecific construct can be expressed recombinantly in a host cell using standard transfection methods.
  • nucleic acid encoding the bispecific construct can be ligated into an expression vector, such as a eukaryotic expression plasmid, such as used by GS gene expression system disclosed in WO 87/04462, WO 89/01036 and EP 338 841 or other expression systems well known in the art.
  • the purified plasmid with the cloned bispecific construct gene can be introduced in eukaryotic host cells, such as CHO-cells or NSO-cells or alternatively other eukaryotic cells like a plant derived cells, fungi or yeast cells.
  • the method used to introduce these genes could be methods described in the art, such as electroporation, lipofectin, lipofectamine or other.
  • cells expressing the bispecific construct can be identified and selected. These cells represent the transfectomas that can then be amplified for their expression level and upscaled to produce bispecific constructs.
  • these cloned bispecific constructs can be expressed in other expression systems, such as E. coli or in complete organisms or can be synthetically expressed.
  • Recombinant bispecific constructs can be isolated and purified from these culture supernatants and/or cells.
  • a bispecific construct of the invention can be isolated and purified using one or more methodologies for protein purification well established in the art.
  • Preferred methods for isolation and purification include, but are not limited to, gel filtration chromatography, affinity chromatography, anion-exchange chromatography and the like.
  • a particularly preferred method is gel filtration chromatography, e.g., using a Superdex 200 column.
  • Isolated and purified bispecific constructs can be evaluated using standard methods such as SDS-PAGE analysis. Accordingly, in one embodiment, the ILT4 antibody or antigen binding fragment thereof is genetically fused to a PD-L1 or PD-1 antibody or antigen binding fragment thereof.
  • the ILT4 antibody or antigen binding fragment thereof and the PD- L1 antibody or antigen binding fragment thereof are chemically conjugated.
  • the PD-L1 or PD-1 antibody or antigen binding fragment thereof further comprises a human IgG1 constant domain.
  • the ILT4 antibody or antigen binding fragment thereof is linked to the C-terminus of the heavy chain of the PD-L1 or PD-1 antibody or antigen binding fragment thereof.
  • the ILT4 antigen binding fragment thereof is a scFv.
  • the ILT4 antibody or antigen binding fragment thereof further comprises a human IgG1 constant domain.
  • the PD-L1 or PD-1 antibody or antigen binding fragment thereof is linked to the C-terminus of the heavy chain of the ILT4 antibody or antigen binding fragment thereof.
  • the PD-L1 or PD-1 antigen binding fragment thereof is a scFv.
  • the bispecific and multispecific constructs of the present invention comprise a modified human Fc domain (e.g., a modified IgG1 Fc domain), for example, (a) a modified human IgG1 Fc domain which comprises non-naturally occurring amino acids 234A, 235Q and 322Q as numbered by the EU index as set forth in Kabat, (b) a modified human IgG1 Fc domain which comprises non-naturally occurring amino acids 252Y, 254T and 256E as numbered by the EU index as set forth in Kabat, and/or (c) a modified human IgG1 Fc domain which comprises non-naturally occurring amino acids 234A, 235Q and 322Q as numbered by the EU index as set forth in Kabat.
  • Exemplary bispecific constructs are set forth below in Tables 2 and 3, wherein the antibody or antigen binding fragments thereof are defined by CDR sequences (Table 2) or variable region sequences (Table 3). Table 2: Exemplary Bispecific Constructs (CDRs)
  • Bispecific and multispecific constructs comprising sequences substantially identical to the aforementioned ILT4 and PD-L1 sequences (i.e., CDR and variable region sequences) also are provided herein (e.g., sequences having conservative sequence modifications and/or sequences at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aforementioned sequences).
  • the bispecific and multispecific constructs exhibit one or more of the following properties: a.
  • ILT4 ligand e.g., HLA-G ligand binding to human ILT4; b. enhancing or increasing cytokine or chemokine release by human macrophages; c. potentiating the activation effects of LPS and IFN ⁇ on macrophages; d. promoting M1 macrophage polarization; e. binding to human ILT4 with an equilibrium dissociation constant Kd of 10 -9 M or less, or alternatively, an equilibrium association constant Ka of 10 +9 M -1 or greater; f. lack of cross-reactivity with other ILT family members; g. cross-reactivity with cynomolgus ILT4; and / or h. inhibiting tumor cells that express ILT4.
  • compositions e.g., a composition comprising one or a combination of any of the antibodies, or antigen binding fragments thereof, the bispecific constructs, or the multispecific constructs described herein, formulated together with a carrier (e.g., a pharmaceutically acceptable carrier).
  • a carrier e.g., a pharmaceutically acceptable carrier
  • the terms “carrier” and “pharmaceutically acceptable carrier” includes any and all solvents, salts, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like that are physiologically compatible.
  • the carrier is suitable for intravenous, intramuscular, subcutaneous, parenteral, spinal or epidermal administration (e.g., by injection or infusion).
  • the active compound i.e., any of the antibodies, or antigen binding fragments thereof, the bispecific constructs, or the multispecific constructs described herein
  • the active compound may be coated in a material to protect the compound from the action of acids and other natural conditions that may inactivate the compound.
  • adjuvants which may be used with the antibodies, or antigen binding fragments thereof, the bispecific constructs, or the multispecific constructs described here include, but are not limited to : Freund's Incomplete Adjuvant and Complete Adjuvant (Difco Laboratories, Detroit, Mich.); Merck Adjuvant 65 (Merck and Company, Inc., Rahway, N.J.); AS-2 (SmithKline Beecham, Philadelphia, Pa.); aluminum salts such as aluminum hydroxide gel (alum) or aluminum phosphate; salts of calcium, iron or zinc; an insoluble suspension of acylated tyrosine; acylated sugars; cationically or anionically derivatised polysaccharides; polyphosphazenes; biodegradable microspheres; cytokines, such as GM-CSF, interleukin-2, - 7, -12, and other like factors; 3D-MPL; CpG oligonucleotide; and monophosphoryl lipid A, for example 3-de-O
  • MPL adjuvants are available from Corixa Corporation (Seattle, Wash; see, for example, U.S. Pat. Nos.4,436,727; 4,877,611; 4,866,034 and 4,912,094).
  • CpG-containing oligonucleotides in which the CpG dinucleotide is unmethylated
  • Immunostimulatory DNA sequences are also described, for example, by Sato et al., Science 273:352, 1996.
  • adjuvants include, for example, saponins, such as Quil A, or derivatives thereof, including QS21 and QS7 (Aquila Biopharmaceuticals Inc., Framingham, Mass.); Escin; Digitonin; or Gypsophila or Chenopodium quinoa saponins; Montanide ISA 720 (Seppic, France); SAF (Chiron, California, United States); ISCOMS (CSL), MF-59 (Chiron); the SBAS series of adjuvants (e.g., SBAS-2 or SBAS-4, available from SmithKline Beecham, Rixensart, Belgium); Detox (Enhanzyn TM ) (Corixa, Hamilton, Mont.); RC-529 (Corixa, Hamilton, Mont.) and other aminoalkyl glucosaminide 4-phosphates (AGPs); polyoxyethylene ether adjuvants such as those described in WO 99/52549A1; synthetic imidazoquinolines such as imiquimod [
  • cytokine, chemokine and co-stimulatory molecules as either protein or peptide, including for example pro-inflammatory cytokines such as Interferon, GM-CSF, IL-1 alpha, IL-1 beta, TGF-alpha and TGF-beta, Th1 inducers such as interferon gamma, IL-2, IL-12, IL- 15, IL-18 and IL-21, Th2 inducers such as IL-4, IL-5, IL-6, IL-10 and IL-13 and other chemokine and co-stimulatory genes such as MCP-1, MIP-1 alpha, MIP-1 beta, RANTES, TCA-3, CD80, CD86 and CD40L; immunostimulatory agents targeting ligands such as CTLA-4 and L-selectin, apoptosis stimulating proteins and peptides such as Fas; synthetic lipid based adjuvants, such as vaxfectin, (
  • a “pharmaceutically acceptable salt” refers to a salt that retains the desired biological activity of the parent compound and does not impart any undesired toxicological effects (see e.g., Berge, S.M., et al. (1977) J. Pharm. Sci.66:1-19). Examples of such salts include acid addition salts and base addition salts.
  • Acid addition salts include those derived from nontoxic inorganic acids, such as hydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydroiodic, phosphorous and the like, as well as from nontoxic organic acids such as aliphatic mono- and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids, aromatic acids, aliphatic and aromatic sulfonic acids and the like.
  • nontoxic inorganic acids such as hydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydroiodic, phosphorous and the like
  • nontoxic organic acids such as aliphatic mono- and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids, aromatic acids, aliphatic and aromatic sulfonic acids and the like.
  • Base addition salts include those derived from alkaline earth metals, such as sodium, potassium, magnesium, calcium and the like, as well as from nontoxic organic amines, such as N,N'-dibenzylethylenediamine, N- methylglucamine, chloroprocaine, choline, diethanolamine, ethylenediamine, procaine and the like.
  • a composition of the present invention can be administered by a variety of methods known in the art. As will be appreciated by the skilled artisan, the route and/or mode of administration will vary depending upon the desired results.
  • the active compounds can be prepared with carriers that will protect the compound against rapid release, such as a controlled release formulation, including implants, transdermal patches, and microencapsulated delivery systems.
  • Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Many methods for the preparation of such formulations are patented or generally known to those skilled in the art. See, e.g., Sustained and Controlled Release Drug Delivery Systems, J.R. Robinson, ed., Marcel Dekker, Inc., New York, 1978.
  • To administer a compound of the invention by certain routes of administration it may be necessary to coat the compound with, or co-administer the compound with, a material to prevent its inactivation.
  • the compound may be administered to a subject in an appropriate carrier, for example, liposomes, or a diluent.
  • Acceptable diluents include saline and aqueous buffer solutions.
  • Liposomes include water-in-oil-in-water CGF emulsions as well as conventional liposomes (Strejan et al. (1984) J. Neuroimmunol.7:27).
  • Carriers include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion.
  • the use of such media and agents for pharmaceutically active substances is known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the pharmaceutical compositions of the invention is contemplated. Supplementary active compounds can also be incorporated into the compositions.
  • compositions typically must be sterile and stable under the conditions of manufacture and storage.
  • the composition can be formulated as a solution, microemulsion, liposome, or other ordered structure suitable to high drug concentration.
  • the carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof.
  • the proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants.
  • isotonic agents for example, sugars, polyalcohols such as mannitol, sorbitol, or sodium chloride in the composition.
  • Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent that delays absorption, for example, monostearate salts and gelatin.
  • Sterile injectable solutions can be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by sterilization microfiltration.
  • dispersions are prepared by incorporating the active compound into a sterile vehicle that contains a basic dispersion medium and the required other ingredients from those enumerated above.
  • the preferred methods of preparation are vacuum drying and freeze-drying (lyophilization) that yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.
  • Dosage regimens are adjusted to provide the optimum desired response (e.g., a therapeutic response). For example, a single bolus may be administered, several divided doses may be administered over time or the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation.
  • the antibodies of the invention may be administered once or twice weekly by subcutaneous or intramuscular injection or once or twice monthly by subcutaneous or intramuscular injection.
  • Dosage unit form refers to physically discrete units suited as unitary dosages for the subjects to be treated; each unit contains a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier.
  • the specification for the dosage unit forms of the invention are dictated by and directly dependent on (a) the unique characteristics of the active compound and the particular therapeutic effect to be achieved, and (b) the limitations inherent in the art of compounding such an active compound for the treatment of sensitivity in individuals.
  • antioxidants examples include: (1) water soluble antioxidants, such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite and the like; (2) oil-soluble antioxidants, such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, alpha-tocopherol, and the like; and (3) metal chelating agents, such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, and the like.
  • water soluble antioxidants such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite and the like
  • oil-soluble antioxidants such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), le
  • formulations of the present invention include those suitable for oral, nasal, topical (including buccal and sublingual), rectal, vaginal and/or parenteral administration.
  • the formulations may conveniently be presented in unit dosage form and may be prepared by any methods known in the art of pharmacy.
  • the amount of active ingredient which can be combined with a carrier material to produce a single dosage form will vary depending upon the subject being treated, and the particular mode of administration.
  • the amount of active ingredient which can be combined with a carrier material to produce a single dosage form will generally be that amount of the composition which produces a therapeutic effect.
  • compositions of this invention which are suitable for vaginal administration also include pessaries, tampons, creams, gels, pastes, foams or spray formulations containing such carriers as are known in the art to be appropriate.
  • Dosage forms for the topical or transdermal administration of compositions of this invention include powders, sprays, ointments, pastes, creams, lotions, gels, solutions, patches and inhalants.
  • parenteral administration and “administered parenterally” as used herein means modes of administration other than enteral and topical administration, usually by injection, and includes, without limitation, intravenous, intramuscular, intraarterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, transtracheal, subcutaneous, subcuticular, intraarticular, subcapsular, subarachnoid, intraspinal, epidural and intrasternal injection and infusion.
  • aqueous and nonaqueous carriers examples include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, and injectable organic esters, such as ethyl oleate.
  • polyols such as glycerol, propylene glycol, polyethylene glycol, and the like
  • vegetable oils such as olive oil
  • injectable organic esters such as ethyl oleate.
  • Proper fluidity can be maintained, for example, by the use of coating materials, such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.
  • These compositions may also contain adjuvants such as preservatives, wetting agents, emulsifying agents and dispersing agents.
  • Prevention of presence of microorganisms may be ensured both by sterilization procedures, supra, and by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents, such as sugars, sodium chloride, and the like into the compositions. In addition, prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents that delay absorption such as aluminum monostearate and gelatin.
  • the compounds of the present invention When the compounds of the present invention are administered as pharmaceuticals, to humans and animals, they can be given alone or as a pharmaceutical composition containing, for example, 0.001 to 90% (more preferably, 0.005 to 70%, such as 0.01 to 30%) of active ingredient in combination with a pharmaceutically acceptable carrier. Regardless of the route of administration selected, the compounds of the present invention, which may be used in a suitable hydrated form, and/or the pharmaceutical compositions of the present invention, are formulated into pharmaceutically acceptable dosage forms by conventional methods known to those of skill in the art. Actual dosage levels of the active ingredients in the pharmaceutical compositions of the present invention may be varied so as to obtain an amount of the active ingredient that is effective to achieve the desired therapeutic response for a particular patient, composition, and mode of administration, without being toxic to the patient.
  • the selected dosage level will depend upon a variety of pharmacokinetic factors including the activity of the particular compositions of the present invention employed, or the ester, salt or amide thereof, the route of administration, the time of administration, the rate of excretion of the particular compound being employed, the duration of the treatment, other drugs, compounds and/or materials used in combination with the particular compositions employed, the age, sex, weight, condition, general health and prior medical history of the patient being treated, and like factors well known in the medical arts.
  • a physician or veterinarian having ordinary skill in the art can readily determine and prescribe the effective amount of the pharmaceutical composition required.
  • a suitable daily dose of a composition of the invention will be that amount of the compound that is the lowest dose effective to produce a therapeutic effect.
  • Such an effective dose will generally depend upon the factors described above. It is preferred that administration be intravenous, intramuscular, intraperitoneal, or subcutaneous, preferably administered proximal to the site of the target.
  • the effective daily dose of a therapeutic composition may be administered as two, three, four, five, six or more sub- doses administered separately at appropriate intervals throughout the day, optionally, in unit dosage forms.
  • compositions can be administered with medical devices known in the art.
  • a therapeutic composition of the invention can be administered with a needleless hypodermic injection device, such as the devices disclosed in U.S. Patent Nos.5,399,163, 5,383,851, 5,312,335, 5,064,413, 4,941,880, 4,790,824, or 4,596,556.
  • a needleless hypodermic injection device such as the devices disclosed in U.S. Patent Nos.5,399,163, 5,383,851, 5,312,335, 5,064,413, 4,941,880, 4,790,824, or 4,596,556.
  • Examples of well-known implants and modules useful in the present invention include: U.S. Patent No.4,487,603, which discloses an implantable micro-infusion pump for dispensing medication at a controlled rate; U.S.
  • Patent No.4,486,194 which discloses a therapeutic device for administering medicants through the skin
  • U.S. Patent No.4,447,233 which discloses a medication infusion pump for delivering medication at a precise infusion rate
  • U.S. Patent No.4,447,224 which discloses a variable flow implantable infusion apparatus for continuous drug delivery
  • U.S. Patent No.4,439,196 which discloses an osmotic drug delivery system having multi-chamber compartments
  • U.S. Patent No.4,475,196 which discloses an osmotic drug delivery system.
  • Many other such implants, delivery systems, and modules are known to those skilled in the art.
  • the antibodies of the invention can be formulated to ensure proper distribution in vivo.
  • the blood-brain barrier excludes many highly hydrophilic compounds.
  • the therapeutic compounds of the invention cross the BBB (if desired)
  • they can be formulated, for example, in liposomes.
  • liposomes For methods of manufacturing liposomes, see, e.g., U.S. Patents 4,522,811; 5,374,548; and 5,399,331.
  • the liposomes may comprise one or more moieties that are selectively transported into specific cells or organs, thus enhance targeted drug delivery (see, e.g., V.V. Ranade (1989) J. Clin. Pharmacol.29:685).
  • Exemplary targeting moieties include folate or biotin (see, e.g., U.S.
  • Patent 5,416,016 to Low et al. mannosides (Umezawa et al., (1988) Biochem. Biophys. Res. Commun.153:1038); antibodies (P.G. Bloeman et al. (1995) FEBS Lett.357:140; M. Owais et al. (1995) Antimicrob. Agents Chemother.39:180); surfactant protein A receptor (Briscoe et al. (1995) Am. J. Physiol.1233:134), different species of which may comprise the formulations of the inventions, as well as components of the invented molecules; p120 (Schreier et al. (1994) J. Biol.
  • the therapeutic compounds of the invention are formulated in liposomes; in a more preferred embodiment, the liposomes include a targeting moiety. In a most preferred embodiment, the therapeutic compounds in the liposomes are delivered by bolus injection to a site proximal to the tumor or infection.
  • the composition must be fluid to the extent that easy syringability exists.
  • a therapeutically effective amount of a therapeutic compound can decrease tumor size, or otherwise ameliorate symptoms in a subject.
  • One of ordinary skill in the art would be able to determine such amounts based on such factors as the subject's size, the severity of the subject's symptoms, and the particular composition or route of administration selected.
  • the composition must be sterile and fluid to the extent that the composition is deliverable by syringe.
  • the carrier can be an isotonic buffered saline solution, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol, and the like), and suitable mixtures thereof.
  • Proper fluidity can be maintained, for example, by use of coating such as lecithin, by maintenance of required particle size in the case of dispersion and by use of surfactants.
  • isotonic agents for example, sugars, polyalcohols such as mannitol or sorbitol, and sodium chloride in the composition.
  • nucleic Acids Also provided herein are isolated nucleic acid molecules encoding the antibodies, or antigen binding fragments thereof, bispecific constructs, and multispecific constructs, as well as expression vectors comprising such nucleic acids and host cells comprising such expression vectors. In one embodiment, a nucleic acid molecule coding for any of the antibodies, or antigen fragments thereof, bispecific constructs, or multispecific constructs described herein is provided.
  • nucleic acid molecule is in the form of an expression vector. In another embodiment, the nucleic acid molecule is in the form of an expression vector which expresses the antibody, or antigen fragment thereof, bispecific construct, or the multispecific construct when administered to a subject in vivo.
  • the nucleic acid molecule comprises a nucleotide sequence encoding an antibody variable region, wherein the antibody variable region comprises the amino acid sequence depicted in SEQ ID NO:9, 10, 19, 20, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, or an amino acid sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to one or more of the aforementioned sequences).
  • the nucleic acid molecule comprises a nucleotide sequence encoding an antibody chain, wherein the chain comprises the amino acid sequence depicted in SEQ ID NO:25, 26, 27, 28, or an amino acid sequence at least 90% identical thereto (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to one or more of the aforementioned sequences).
  • the nucleic acid molecule comprises a nucleotide sequence encoding heavy and light chain variable regions of an antibody, wherein the heavy and light chain variable regions respectively comprise the amino acid sequences depicted in SEQ ID NOs:9 and 10, SEQ ID NOs:19 and 20, or amino acids sequences at least 90% identical to the aforementioned sequences (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical).
  • the nucleic acid molecule comprises a nucleotide sequence encoding heavy and light chains of an antibody, wherein the heavy and light chains respectively comprise the amino acid sequences depicted in SEQ ID NOs:25 and 26, SEQ ID NOs:27 and 28, or amino acids sequences at least 90% identical to the aforementioned sequences (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical).
  • vector as used herein, is intended to refer to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked.
  • vectors refers to a circular double stranded DNA loop into which additional DNA segments may be ligated.
  • viral vector Another type of vector is a viral vector, wherein additional DNA segments may be ligated into the viral genome.
  • Certain vectors are capable of autonomous replication in a host cell into which they are introduced (e.g., bacterial vectors having a bacterial origin of replication and episomal mammalian vectors). Other vectors (e.g., non-episomal mammalian vectors) can be integrated into the genome of a host cell upon introduction into the host cell, and thereby are replicated along with the host genome.
  • certain vectors are capable of directing the expression of genes to which they are operatively linked.
  • recombinant expression vectors Such vectors are referred to herein as “recombinant expression vectors”(or simply, “expression vectors”).
  • expression vectors of utility in recombinant DNA techniques are often in the form of plasmids.
  • plasmid and “vector” may be used interchangeably as the plasmid is the most commonly used form of vector.
  • the invention is intended to include such other forms of expression vectors, such as viral vectors (e.g., replication defective retroviruses, adenoviruses and adeno-associated viruses), which serve equivalent functions.
  • the term “recombinant host cell” (or simply “host cell”), as used herein, is intended to refer to a cell into which a recombinant expression vector has been introduced.
  • the term “coadministered” as used herein includes any or all of simultaneous, separate, or sequential administration of the antibodies, antigen binding fragments thereof, bispecific constructs, or multispecific constructs described herein with adjuvants and other agents, including administration as part of a dosing regimen.
  • the combination therapy can include administering any of the antibodies, antigen binding fragments thereof, bispecific constructs, and/or multispecific constructs described herein with at least one or more additional therapeutic agents, such as anti-inflammatory agents, DMARDs (disease-modifying anti-rheumatic drugs), immunosuppressive agents, chemotherapeutics, radiation therapy, other antibodies, cytotoxins and/or drugs, as well as adjuvants, immunostimulatory agents and/or immunosuppressive agents.
  • additional therapeutic agents such as anti-inflammatory agents, DMARDs (disease-modifying anti-rheumatic drugs), immunosuppressive agents, chemotherapeutics, radiation therapy, other antibodies, cytotoxins and/or drugs, as well as adjuvant
  • Chemotherapeutic agents suitable for coadministration with the antibodies, antigen binding fragments thereof, bispecific constructs, and/or multispecific constructs described herein in the treatment of tumors include, for example: taxol, cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicin, doxorubicin, daunorubicin, dihydroxy anthracin dione, mitoxantrone, mithramycin, actinomycin D, 1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol, and puromycin and analogs or homologs thereof.
  • Further agents include, for example, antimetabolites (e.g., methotrexate, 6-mercaptopurine, 6-thioguanine, cytarabine, 5-fluorouracil decarbazine), alkylating agents (e.g., mechlorethamine, thioepa chlorambucil, melphalan, carmustine (BSNU) and lomustine (CCNU), cyclothosphamide, busulfan, dibromomannitol, streptozotocin, mitomycin C, and cis-dichlorodiamine platinum (II) (DDP) cisplatin), anthracyclines (e.g., daunorubicin (formerly daunomycin) and doxorubicin), antibiotics (e.g., dactinomycin (formerly actinomycin), bleomycin, mithramycin, and anthramycin (AMC)), and anti-mitotic agents (e.g., vincri
  • agents that delete or inhibit immunosuppressive activities for example, by immune cells (for example regulatory T-cells, NKT cells, macrophages, myeloid-derived suppressor cells, immature or suppressive dendritic cells) or suppressive factors produced by the tumor or host cells in the local microenvironment of the tumor (for example, TGF ⁇ , indoleamine 2,3 dioxygenase – IDO), may also be administered with the binding domains, antibodies, antigen binding fragments thereof, bispecific constructs, and/or multispecific constructs described herein.
  • agents include antibodies and small molecule drugs such as IDO inhibitors such as 1 methyl tryptophan or derivatives.
  • Suitable agents for coadministration with the antibodies, antigen binding fragments thereof, bispecific constructs, and/or multispecific constructs described herein for treatment of such immune disorders include for example, immunosuppressive agents such as rapamycin, cyclosporin and FK506; anti-TNF agents such as etanercept, adalimumab and infliximab; and steroids.
  • Examples of specific natural and synthetic steroids include, for example: aldosterone, beclomethasone, betamethasone, budesonide, cloprednol, cortisone, cortivazol, deoxycortone, desonide, desoximetasone, dexamethasone, difluorocortolone, fluclorolone, flumethasone, flunisolide, fluocinolone, fluocinonide, fluocortin butyl, fluorocortisone, fluorocortolone, fluorometholone, flurandrenolone, fluticasone, halcinonide, hydrocortisone, icomethasone, meprednisone, methylprednisolone, paramethasone, prednisolone, prednisone, tixocortol and triamcinolone.
  • Suitable agents for coadministration with the antibodies, antigen binding fragments thereof, bispecific constructs, and/or multispecific constructs described herein for inducement or enhancement of an immune response include, for example, adjuvants and/or immunostimulatory agents, non-limiting examples of which have been disclosed hereinbefore.
  • the immunostimulatory agent is a TLR3 agonist, such as Poly IC.
  • the term “immunostimulatory agent” includes, but is not limited to, compounds capable of stimulating antigen presenting cells (APCs), such as dendritic cells (DCs) and macrophages.
  • suitable immunostimulatory agents for use in the present invention are capable of stimulating APCs, so that the maturation process of the APCs is accelerated, the proliferation of APCs is increased, and/or the recruitment or release of co-stimulatory molecules (e.g., CD80, CD86, ICAM-1, MHC molecules and CCR7) and pro-inflammatory cytokines (e.g., IL-1 ⁇ , IL-6, IL-12, IL-15, and IFN- ⁇ ) is upregulated.
  • co-stimulatory molecules e.g., CD80, CD86, ICAM-1, MHC molecules and CCR7
  • pro-inflammatory cytokines e.g., IL-1 ⁇ , IL-6, IL-12, IL-15, and IFN- ⁇
  • Suitable immunostimulatory agents are also capable of increasing T cell proliferation.
  • Such immunostimulatory agents include, but are not be limited to, CD40 ligand; FLT 3 ligand; cytokines, such as IFN- ⁇ , IFN- ⁇ , IFN- ⁇ and IL-2; colony-stimulating factors, such as G-CSF (granulocyte colony-stimulating factor) and GM-CSF (granulocyte-macrophage colony- stimulating factor); an CTLA-4 antibody, PD-1 antibody, 41BB antibody, or OX-40 antibody; LPS (endotoxin); ssRNA; dsRNA; Bacille Calmette-Guerin (BCG); Levamisole hydrochloride; and intravenous immune globulins.
  • CD40 ligand such as CD40 ligand
  • FLT 3 ligand such as cytokines, such as IFN- ⁇ , IFN- ⁇ , IFN- ⁇ and IL-2
  • colony-stimulating factors such as G-CSF (granulocyte colony-stimulating factor) and GM
  • an immunostimulatory agant may be a Toll-like Receptor (TLR) agonist.
  • the immunostimulatory agent may be a TLR3 agonist such as double-stranded inosine:cytosine polynucleotide (Poly I:C, for example available as AmpligenTM from Hemispherx Bipharma, PA, US or Poly IC:LC from Oncovir) or Poly A:U; a TLR4 agonist such as monophosphoryl lipid A (MPL) or RC-529 (for example as available from GSK, UK); a TLR5 agonist such as flagellin; a TLR7 or TLR8 agonist such as an imidazoquinoline TLR7 or TLR 8 agonist, for example imiquimod (eg AldaraTM) or resiquimod and related imidazoquinoline agents (for example as available from 3M Corporation); or a TLR 9 agonist such as a deoxynucleotide with unmethylated CpG
  • Such immunostimulatory agents may be administered simultaneously, separately or sequentially with the antibodies, antigen binding fragments thereof, bispecific constructs, and/or multispecific constructs described herein.
  • methods of methods of inducing or enhancing an immune response and methods of treating cancer by administering the bispecific constructs, multispecific constructs, antibodies, or antigen binding fragments thereof, or compositions described herein to a patient in need thereof.
  • inducing an immune response and “enhancing an immune response” are used interchangeably and refer the stimulation of an immune response (i.e., either passive or adaptive) to a particular antigen.
  • the terms “treat,” “treating,” and “treatment,” as used herein, refer to therapeutic or preventative measures described herein.
  • treatment employ administration to a subject, in need of such treatment, a bispecific construct, multispecific construct, antibody, antigen binding fragment thereof, or composition as described herein, for example, a subject in need of an enhanced immune response against a particular antigen or a subject who ultimately may acquire such a disorder, in order to prevent, cure, delay, reduce the severity of, or ameliorate one or more symptoms of the disorder or recurring disorder, or in order to prolong the survival of a subject beyond that expected in the absence of such treatment.
  • effective dose or “effective dosage” is defined as an amount sufficient to achieve or at least partially achieve the desired effect.
  • therapeutically effective dose is defined as an amount sufficient to cure or at least partially arrest the disease and its complications in a patient already suffering from the disease.
  • Amounts effective for this use will depend upon the severity of the disorder being treated and the general state of the patient’s own immune system.
  • the term “patient” includes human and other mammalian subjects that receive either prophylactic or therapeutic treatment.
  • the term “inhibits growth” is intended to include any measurable decrease in the growth of a cell, e.g., the inhibition of growth of a cell by at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99%, or 100%.
  • methods for inducing or enhancing an immune response (e.g., against an antigen) in a subject comprising administering to the subject any one of the antibodies, or antigen binding fragments thereof, bispecific constructs, multispecific constructs, or the compositions described herein, in an amount effective to induce or enhance an immune response in the subject (e.g., against an antigen).
  • methods of for treating cancer in a subject comprising administering to the subject any one of the antibodies, or antigen binding fragments thereof, bispecific constructs, multispecific constructs, or the compositions described herein, in an amount effective to treat the condition or disease.
  • methods for treating cancer in a subject comprising administering to the subject any one of the ILT4 antibodies, or antigen binding fragments thereof, described herein in combination with another antibody or antigen binding fragment thereof, e.g., any one of the PD-L1 or PD-1 antibodies, or antigen binding fragments thereof, described herein.
  • the ILT4 antibody, or antigen binding fragment thereof, and the PD-L1 or PD-1 antibody, or antigen binding fragment thereof are administered separately.
  • the ILT4 antibody, or antigen binding fragment thereof, and the PD-L1 or PD-1 antibody, or antigen binding fragment thereof are administered sequentially.
  • the ILT4 antibody, or antigen binding fragment thereof can be administered first followed by (e.g., immediately followed by) administration of the PD-L1 or PD-1 antibody, or antigen binding fragment thereof, or vice versa.
  • the ILT4 antibody, or antigen binding fragment thereof, and the PD-L1 or PD-1 antibody, or antigen binding fragment thereof are administered together.
  • the ILT4 antibody, or antigen binding fragment thereof, and the PD-L1 or PD-1 antibody, or antigen binding fragment thereof are administered simultaneously.
  • the ILT4 antibody, or antigen binding fragment thereof, and the PD-L1 or PD-1 antibody, or antigen binding fragment thereof are simultaneously administered in a single formulation.
  • the ILT4 antibody, or antigen binding fragment thereof, and the PD-L1 or PD- 1 antibody, or antigen binding fragment thereof are formulated for separate administration and are administered concurrently or sequentially. Such concurrent or sequential administration preferably results in both antibodies being simultaneously present in treated patients.
  • administration of any of the ILT4 antibodies, or antigen binding fragment thereof, described herein in combination with any of the PD-L1 or PD-1 antibodies, or antigen binding fragments thereof, described herein results in synergistic effects (e.g., in enhancing immune responses in vivo) as compared to use of either antibody alone.
  • the subject can be, for example, one who suffers from a condition or disease in which stimulation of an immune response is desired.
  • the condition or disease is cancer.
  • Types of cancers include, but are not limited to, leukemia, acute lymphocytic leukemia, acute myelocytic leukemia, myeloblasts promyelocyte myelomonocytic monocytic erythroleukemia, chronic leukemia, chronic myelocytic (granulocytic) leukemia, chronic lymphocytic leukemia, mantle cell lymphoma, primary central nervous system lymphoma, Burkitt’s lymphoma and marginal zone B cell lymphoma, Polycythemia vera Lymphoma, Hodgkin's disease, non-Hodgkin' s disease, multiple myeloma, Waldenstrom's macroglobulinemia, heavy chain disease, solid tumors, sarcomas, and carcinomas, fibrosarcoma, myxosarcoma, liposarcoma, chrondrosarcoma, osteogenic sarcoma, osteo
  • Particular cancers include ILT4-expressing tumors selected from the group consisting of chronic lymphocytic leukemia, mantle cell lymphoma, primary central nervous system lymphoma, Burkitt’s lymphoma and marginal zone B cell lymphoma.
  • Other disease indications include bacterial, fungal, viral and parasitic infectious diseases.
  • the methods of inducing or enhancing an immune response (e.g., against an antigen) in a subject described herein can further comprise administering the antigen to the subject.
  • the term “antigen” refers to any natural or synthetic immunogenic substance, such as a protein, peptide, hapten, polysaccharide and/or lipid.
  • the bispecific construct, multispecific construct, antibody, antigen binding fragment thereof, or composition described herein and antigen can be administered at the same time or, alternatively, the bispecific construct, multispecific construct, antibody, antigen binding fragment thereof, or composition can be administered before or after the antigen is administered.
  • a bispecific construct, multispecific construct, antibody, antigen binding fragment thereof, or composition described herein is administered in combination with a vaccine, to enhance the immune response against the vaccine antigen, for example a tumor antigen (to thereby enhance the immune response against the tumor) or an antigen from an infectious disease pathogen (to thereby enhance the immune response against the infectious disease pathogen).
  • a vaccine antigen can comprise, for example, an antigen or antigenic composition capable of eliciting an immune response against a tumor or against an infectious disease pathogen such as a virus, a bacteria, a parasite or a fungus.
  • the antigen or antigens be derived from tumors, such as the various tumor antigens previously disclosed herein.
  • the antigen or antigens can be derived from pathogens such as viruses, bacteria, parasites and/or fungi.
  • Preferred antigens to be co-administered with the antibodies, or antigen binding fragments thereof, bispecific constructs, multispecific constructs, or the compositions of described herein include tumor antigens and vaccine antigens (e.g., bacterial, viral or other pathogen antigens against which protective immunity is desired to be raised in a subject for purposes of vaccination).
  • vaccine antigens e.g., bacterial, viral or other pathogen antigens against which protective immunity is desired to be raised in a subject for purposes of vaccination.
  • suitable pathogen antigens include tumor- associated antigens (TAAs), including but not limited to, sequences comprising all or part of the sequences of EGFR, EGFRvIII, gp100 or Pmel17, HER2/neu, mesothelin, CEA, MART1, MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MUC-1, GPNMB, HMW-MAA, TIM1, ROR1, CD19 and germ cell derived tumor antigens.
  • TAAs tumor- associated antigens
  • suitable antigens include viral antigens for the prevention or treatment of viral diseases.
  • viral antigens include, but are not limited to, HIV-1 env, HBsAg, HPV, FAS, HSV-1, HSV-2, p17, ORF2 and ORF3 antigens.
  • viral antigens or antigenic determinants can be derived from, for example,: Cytomegalovirus (especially Human, such as gB or derivatives thereof); Epstein Barr virus (such as gp350); flaviviruses (e.g.
  • hepatitis virus such as hepatitis B virus (for example Hepatitis B Surface antigen such as the PreSl, PreS2 and S antigens described in EP-A-414374; EP-A-0304578, and EP-A- 198474), hepatitis A virus, hepatitis C virus and hepatitis E virus; HIV-1, (such as tat, nef, gpl20 or gpl60); human herpes viruses, such as gD or derivatives thereof or Immediate Early protein such as ICP27 from HSV1 or HSV2; human papilloma viruses (for example HPV6, 11, 16, 18); Influenza virus (whole live or inactivated virus, split influenza virus, grown in eggs or MDCK cells, or Vero cells or whole flu virosomes (as described by Gluck, Vaccine, 1992,10, 915
  • bacterial antigens include, but are not limited to, Toxoplasma gondii or Treponema pallidum.
  • the bacterial antigens can be in the treatment or prevention of various bacterial diseases such as Anthrax, Botulism, Tetanus, Chlamydia, Cholera, Diphtheria, Lyme Disease, Syphilis and Tuberculosis.
  • Bacterial antigens or antigenic determinants can be derived from, for example: Bacillus spp., including B. anthracis (e.g., botulinum toxin); Bordetella spp, including B.
  • pertussis for example pertactin, pertussis toxin, filamenteous hemagglutinin, adenylate cyclase, fimbriae
  • Borrelia spp. including B. burgdorferi (eg OspA, OspC, DbpA, DbpB), B. garinii (eg OspA, OspC, DbpA, DbpB), B. afzelii (eg OspA, OspC, DbpA, DbpB), B. andersonii (eg OspA, OspC, DbpA, DbpB), B.
  • B. burgdorferi eg OspA, OspC, DbpA, DbpB
  • B. garinii eg OspA, OspC, DbpA, DbpB
  • B. afzelii eg Osp
  • C. jejuni for example toxins, adhesins and invasins
  • C. coli Chlamydia spp., including C. trachomatis (eg MOMP, heparin-binding proteins), C. pneumonie (eg MOMP, heparin-binding proteins), C. psittaci; Clostridium spp., including C. tetani (such as tetanus toxin), C. botulinum (for example botulinum toxin), C. difficile (eg clostridium toxins A or B); Corynebacterium spp., including C.
  • C. trachomatis eg MOMP, heparin-binding proteins
  • C. pneumonie eg MOMP, heparin-binding proteins
  • C. psittaci Clostridium spp., including C. tetani (such as tetanus toxin), C. bot
  • diphtheriae eg diphtheria toxin
  • Ehrlichia spp. including E. equi and the agent of the Human Granulocytic Ehrlichiosis
  • Rickettsia spp including R.rickettsii
  • Enterococcus spp. including E. faecalis, E. faecium
  • Escherichia spp including enterotoxic E. coli (for example colonization factors, heat-labile toxin or derivatives thereof, or heat-stable toxin), enterohemorragic E. coli, enteropathogenic E. coli (for example shiga toxin-like toxin); Haemophilus spp., including H.
  • influenzae type B eg PRP
  • non-typable H. influenzae for example OMP26, high molecular weight adhesins, P5, P6, protein D and lipoprotein D, and fimbrin and fimbrin derived peptides (see for example US 5,843,464)
  • Helicobacter spp including H. pylori (for example urease, catalase, vacuolating toxin); Pseudomonas spp, including P. aeruginosa; Legionella spp, including L. pneumophila ; Leptospira spp., including L. interrogans; Listeria spp., including L.
  • Moraxella spp including M catarrhalis, also known as Branhamella catarrhalis (for example high and low molecular weight adhesins and invasins); Morexella Catarrhalis (including outer membrane vesicles thereof, and OMP106 (see for example W097/41731)); Mycobacterium spp., including M. tuberculosis (for example ESAT6, Antigen 85A, -B or -C), M. bovis, M. leprae, M. avium, M. paratuberculosis, M. smegmatis; Neisseria spp, including N. gonorrhea and N.
  • M catarrhalis also known as Branhamella catarrhalis (for example high and low molecular weight adhesins and invasins); Morexella Catarrhalis (including outer membrane vesicles thereof, and OMP106 (see for example W097/41731)
  • meningitidis for example capsular polysaccharides and conjugates thereof, transferrin-binding proteins, lactoferrin binding proteins, PilC, adhesins
  • Neisseria mengitidis B including outer membrane vesicles thereof, and NspA (see for example WO 96/29412); Salmonella spp, including S. typhi, S. paratyphi, S. choleraesuis, S. enteritidis; Shigella spp, including S. sonnei, S. dysenteriae, S. flexnerii; Staphylococcus spp., including S. aureus, S. epidermidis; Streptococcus spp, including S.
  • pneumonie e.g., capsular polysaccharides and conjugates thereof, PsaA, PspA, streptolysin, choline-binding proteins
  • PsaA capsular polysaccharides and conjugates thereof
  • PspA protein antigen Pneumolysin
  • mutant detoxified derivatives thereof see for example WO 90/06951; WO 99/03884
  • Treponema spp. including T. pallidum (eg the outer membrane proteins), T. denticola, T. hyodysenteriae
  • Vibrio spp including V.
  • cholera for example cholera toxin
  • Yersinia spp including Y. enterocolitica (for example a Yop protein), Y. pestis, Y. pseudotuberculosis.
  • Parasitic/fungal antigens or antigenic determinants can be derived from, for example,: Babesia spp., including B. microti; Candida spp., including C. albicans; Cryptococcus spp., including C. neoformans; Entamoeba spp., including E. histolytica; Giardia spp., including ;G. lamblia; Leshmania spp., including L. major; Plasmodium.
  • antigens and antigenic determinants can be used in many different forms.
  • antigens or antigenic determinants can be present as isolated proteins or peptides (for example in so-called "subunit vaccines") or, for example, as cell-associated or virus- associated antigens or antigenic determinants (for example in either live or killed pathogen strains). Live pathogens will preferably be attenuated in known manner.
  • antigens or antigenic determinants may be generated in situ in the subject by use of a polynucleotide coding for an antigen or antigenic determinant (as in so-called "DNA vaccination"), although it will be appreciated that the polynucleotides which can be used with this approach are not limited to DNA, and may also include RNA and modified polynucleotides as discussed above.
  • a vaccine antigen can also be targeted, for example to particular cell types or to particular tissues.
  • the vaccine antigen can be targeted to Antigen Presenting Cells (APCs), for example by use of agents such as antibodies targeted to APC-surface receptors such as DEC-205, for example as discussed in WO 2009/061996 (Celldex Therapeutics, Inc), or the Mannose Receptor (CD206) for example as discussed in WO 03040169 (Medarex, Inc.).
  • kits e.g., diagnostic kits
  • Kits comprising one or more ILT4 antibody or antigen binding fragment thereof, bispecific constructs, multispecific constructs, or compositions as described herein, optionally with instructions for use.
  • Kits may also include informative pamphlets, for example, pamphlets informing one how to use reagents to practice a method disclosed herein.
  • the antigen i.e., 5-20 micrograms soluble recombinant ILT4 antigen in PBS
  • the antigen was mixed at 1:1 ratio with MPL plus TDM adjuvant system (Sigma®). Mice were injected with 200 microliters of the prepared antigen into the peritoneal cavity approximately every 14 days. Animals that developed anti-ILT4 titers were given an intravenous injection of 1-10 micrograms soluble recombinant ILT4 antigen three to four days prior to fusion. Mouse spleens were harvested, and the isolated splenocytes used for hybridoma preparation.
  • the P3x63Ag8.653 murine myeloma cell line (ATCC CRL 1580) was used for fusions which was cultured in RPMI 1640 (Invitrogen®) containing 10% FBS. Additional media supplements were added to the hybridoma growth media, which included: up to 10% Hybridoma Cloning Supplement (Sigma), 10% FBS (Sigma), L-glutamine (Gibco®) 0.1% gentamycin (Gibco), 2-mercaptoethanol (Gibco), with HAT (Sigma; 1.0 x 10 4 M hypoxanthine, 4.0 x 10 -7 M aminopterin, 1.6 x 10 -5 M thymidine media.
  • Spleen cells were mixed with the P3x63Ag8.653 myeloma cells in a 6:1 ratio and pelleted by centrifugation. Polyethylene glycol was added dropwise with careful mixing to facilitate fusion. Hybridomas were cultured for two to three weeks until visible colonies become established. Supernatant was harvested and used for initial screening for mouse IgG via ELISA using a human soluble ILT4 fusion protein and a mouse Fc specific detection. IgG positive supernatants were then assayed for ILT4 specificity via flow cytometry. The hybridomas were also screened for cross-reactivity with cynomolgus macaque ILT4 and all were positive for binding.
  • Hybridoma cells were expanded and cell pellets were frozen for RNA isolation and sequencing.
  • the V H and V L coding regions of human monoclonal antibodies were identified using RNA from the corresponding hybridomas.
  • RNA was reverse transcribed to cDNA, the V coding regions were amplified by PCR and the PCR product was sequenced, inserted into human IgG4 vector, transiently expressed as IgG4 chimeric antibodies and purified by protein A column chromatography which led to the isolation of two antibodies of particular interest, the variable region sequences of which were designated 7A3 (SEQ ID NOs: 9 and 10) and 7B1 (SEQ ID NOs: 19 and 20)).
  • Example 2 Generation of Humanized Antibodies
  • VH and VL domains parental heavy and light chain variable region domains
  • VH and VL domains parental heavy and light chain variable region domains
  • the original mouse variable sequences of antibodies 7A3 and 7B1 were aligned to all human germline sequences.
  • the original mouse and closest matching germline sequences were analyzed for sequence liabilities and the most appropriate germline frameworks selected.
  • Complementarity determining regions (CDRs) from the parent antibody were grafted onto an appropriate number of human frameworks and back mutations were introduced as necessary.
  • Four heavy chain and four light chain humanized variants were designed for antibody 7A3.
  • the 7A3 heavy chain variants were designated: 7A3-H1 (SEQ ID NO:97), 7A3-H2 (SEQ ID NO:9), 7A3-H3 (SEQ ID NO:98) and 7A3-H4 (SEQ ID NO: 99).
  • the 7A3 light chain variants were designated: 7A3-L1 (SEQ ID NO:10), 7A3-L2 (SEQ ID NO:100), 7A3- L3 (SEQ ID NO:101) and 7A3-L4 (SEQ ID NO:102).
  • Four heavy chain and four light chain humanized variants were designed for antibody 7B1.
  • the 7B1 heavy chain variants were designated: 7B1-H1 (SEQ ID NO:103), 7B1-H2 (SEQ ID NO:19), 7B1-H3 (SEQ ID NO:104) and 7B1-H4 (SEQ ID NO:105).
  • the 7B1 light chain variants were designated: 7B1-L1 (SEQ ID NO:20), 7B1-L2 (SEQ ID NO:106), 7B1- L3 (SEQ ID NO:107) and 7B1-L4 (SEQ ID NO:108). Pairing of these variable domain sequences is shown in Table 4.
  • Antibodies 7A3 VH6-L17 and 7B1 VH10-L21 were protein A purified, their Fc domains were mutated (AQQ), and selected for further investigation as described below.
  • Table 4 Heavy and Light Chain Pairings
  • Example 3 Determination of affinity and rate constants of humanized monoclonal antibodies by bio-layer interferometry (BLI) Binding affinity and binding kinetics of various humanized ILT4 antibodies were examined by bio-layer interferometry (BLI) using an OctetTM QK e instrument (ForteBio Sartorius®, Fremont, CA) according to the manufacturer’s guidelines.
  • Purified chimeric antibodies (7A3-huG4 and 7B1-huG4) and humanized antibodies (7A3 VH6-L17, 7A3 VH6-L18, 7A3 VH6-L20, 7B1 VH10-L21, 7B1 VH10-L22 and 7B1 VH10-L24) were captured on Anti-Human Fc Capture (AHC) biosensors (Fortebio Product No.18-5060).
  • Each antibody was prepared in dilution buffer (10mMPO4+150mM NaCl+1mg/mL BSA+ 0.05%Tween 20, pH 7.2) to 0.5 ⁇ g/mL and loaded on freshly hydrated and pre-conditioned AHC biosensors for 300 seconds at 30 o C and 1000rpm plate shake speed.
  • dilution buffer 10mMPO4+150mM NaCl+1mg/mL BSA+ 0.05%Tween 20, pH 7.2
  • Binding was determined by exposing seven of the antibody loaded biosensors to analyte: soluble human ILT4-HIS (His-tagged ILT4 extracellular domain).
  • Affinity measurements were determined using 2-fold serial dilutions of analyte ranging from 25 to 0.4nM in dilution buffer at 30 o C and 1000rpm plate shake speed.
  • association and dissociation curves were fitted to a 1:1 binding model using the data analysis software according to the manufacturer’s guidelines.
  • Example 4 Binding of chimeric and humanized monoclonal antibodies to human ILT4 using ELISA Microtiter plates were coated with recombinant human ILT4-kappa in PBS, and then blocked with 5% bovine serum albumin in PBS.
  • Example 5 Binding of chimeric and humanized monoclonal antibodies to cells expressing human ILT4 Antibodies were tested for binding to human HEK293 cell lines expressing human ILT4 on their surface.
  • Protein A purified chimeric monoclonal antibodies (7A3-huG4, 7B1- huG4), various humanized versions (7A3 VH6-L17, 7A3 VH6-L18, 7A3 VH6-L20, 7B1 VH10-L21, 7B1 VH10-L22 and 7B1 VH10-L24) and isotype controls were incubated with HEK293 cells expressing human ILT4 at room temperature on a plate shaker. After 20 minutes, the cells were washed with PBS containing 0.1% BSA and 0.05% NaN3 (PBA) and the bound antibodies were detected by incubating the cells with a PE labeled goat anti-human IgG Fc-specific probe.
  • Example 6 Induction of TNF- ⁇ production by chimeric and humanized monoclonal antibodies in macrophages Macrophages were derived from human monocytes as follows: PBMCs were added to T175cm 2 flasks and monocytes allowed to adhere for approximately 2 hours at 37 o C, 6%CO 2 .
  • the non-adherent cells were removed and the monocytes cultured for 7 days in RPMI containing 10% FBS and 50 ng/mL M-CSF (R&D Systems®). The cells were then incubated in the presence of protein A purified chimeric monoclonal antibodies (7A3-huG4, 7B1-huG4), their humanized versions (7A3 VH6-L17, 7A3 VH6-L18, 7A3 VH6-L20, 7B1 VH10-L21, 7B1 VH10-L22 and 7B1 VH10-L24) and isotype controls and of 50ng/mL LPS (Invivogen) at 37oC, 6% CO 2 .
  • protein A purified chimeric monoclonal antibodies (7A3-huG4, 7B1-huG4), their humanized versions (7A3 VH6-L17, 7A3 VH6-L18, 7A3 VH6-L20, 7B1 VH10-L
  • FIGs.5A and 5B show the increase in TNF- ⁇ production with the various ILT4 antibodies.
  • Example 7 Induction of TNF- ⁇ and MIP1- ⁇ production by humanized monoclonal antibodies in macrophages Human PBMCs were differentiated with MCSF (100 ng/mL) for 7 days. Following differentiation, human macrophages were plated at 1.5x10 6 cells/well and allowed to adhere overnight.
  • Example 8 Gene expression analysis of humanized monoclonal antibodies in macrophages Human PBMCs were differentiated with MCSF (100 ng/mL) for 7 days. After differentiation human macrophages were plated at 1.5x10 6 cells/well and allowed to adhere overnight.
  • Example 9 Cross-reactivity of humanized monoclonal antibodies: binding to cells expressing ILT family members Protein A purified humanized monoclonal antibodies 7A3 VH6-L17 and 7B1 VH10- L21 and isotype controls were incubated with CHO cells expressing human ILT family members with highest homology to ILT4, e.g., LILRA1, LILRA2 (ILT1), LILRA4 (ILT7), LILRA5 (ILT11), LILRB1 (ILT2) and LILRB2 at room temperature on a plate shaker.
  • LILRA1, LILRA2 (ILT1)
  • LILRA4 LILRA4
  • LILRA5 LILRB1
  • LILRB2 LILRB2
  • Dendritic cells were prepared as follows: PBMC’s were added to T175cm 2 flasks and monocytes allowed to adhere for approximately 2 hours at 37oC, 6%CO 2 . The non-adherent cells were removed and the monocytes cultured for 7 days in RPMI containing 10% FBS, 100 ng/mL GM-CSF (R&D Systems) and 10 ng/mL IL-4 (R&D Systems). Protein A purified monoclonal antibodies 7A3 VH6-L17 and 7B1 VH10-L21 and isotype controls were incubated with human monocytes, macrophages and dendritic cells at room temperature on a plate shaker.
  • the cells were washed with PBS containing 0.1% BSA and 0.05% NaN 3 (PBA) and the bound antibodies were detected by incubating the cells with a PE labeled goat anti-human IgG Fc-specific probe.
  • PBA PBS containing 0.1% BSA and 0.05% NaN 3
  • the excess probe was washed from the cells with PBA and the cell associated fluorescence was determined by analysis using a FACSCanto II TM instrument (BD Biosciences, NJ, USA) according to the manufacturer’s directions. Representative binding is shown in FIGs. 9A, 9B, and 9C.
  • Example 11 Construction and production of bispecific antibodies Tetravalent bispecific antibody constructs were developed using a mutated fully human IgG1 backbone for a PD-L1 monoclonal antibody sequence (9H9; see SEQ ID NOs: 87 and 88 of WO2019204462 for heavy and light chain sequences) and the scFv of the ILT4 monoclonal antibody genetically linked to the C-terminus of the 9H9 heavy chain through a linker.
  • Such bispecific antibodies were created with scFv versions of both 7A3 and 7B1 antibodies.
  • the humanized antibody scFv sequences used in the bispecifics were taken from 7A3 VH6-L17 and 7B1 VH10-L21, respectively.
  • the Fc domain was mutated (AQQ) and certain other amino acid residues were also modified. These constructs are denoted 9H9-7A3 HL and 9H9-7B1 HL, respectively, in which the scFv is in the VH-VL orientation.
  • Alternative bispecific antibody constructs were created with the heavy and light chains of the anti-ILT4 scFv in the reverse orientation, in which the scFv is in the VL-VH orientation.
  • 9H9-7A3 LH and 9H9-7B1 LH respectively. The same 9H9 light chain was used in all four cases.
  • tetravalent bispecific antibodies include the following: Key: Bold double underlined: 9H9 Variable region Bold single underlined: Constant domains (including embedded dotted underline) Italic: anti-ILT4 scFv Italic underlined: linkers Dotted underlined: modified amino acid residues 9H9-7A3 HL EVQLVESGGGLVQPGGSLRLSCAASGGIISTYWMSWVRQAPGKGLEWVANIKQ DGSEKYYVDSVKGRFTISRDNAKNSLYLQMNSLRVEDTAMYYCARDRPVAGAS ALWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSW NSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDK KVEPKSCDKTHTCPPCPAPEAQGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVS HEDPEVKFN
  • FIG.10A shows a schematic depiction of the bispecific constructs.
  • FIG.10B shows an alternative bispecific construct with an anti-PD-1 antibody in place of the anti-PD-L1 antibody.
  • Example 12 Determination of affinity and rate constants of humanized bispecific antibodies by bio-layer interferometry (BLI) Binding affinity and binding kinetics of various human ILT4 bispecific antibodies were examined by bio-layer interferometry (BLI) using an Octet TM QK e instrument (ForteBio Sartorius, Fremont, CA) according to the manufacturer’s guidelines.
  • BBI bio-layer interferometry
  • Binding was determined by exposing six of the antibody loaded biosensors to analyte: soluble human ILT4-HIS (Celldex in-house reagent). Affinity measurements were determined using 2-fold serial dilutions of analyte ranging from 25 to 0.4nM in dilution buffer at 30 o C and 1000rpm plate shake speed. Association of the antibody loaded biosensors in analyte wells was carried out for 300 seconds, the biosensors were then moved to dilution buffer wells for 1500sec for dissociation measurements. Corresponding controls were conducted in each case by keeping the remaining biosensor with captured antibody in dilution buffer wells for association and dissociation steps.
  • the data for the control biosensor was used to subtract background and account for biosensor drift and antibody dissociation from the biosensors.
  • Fortebio’s Data Analysis Software version 8.2.0.7 (ForteBio Sartorius, Fremont, CA) was used in each case to derive kinetic parameters from the concentration series of analyte in dilution buffer binding to captured antibody.
  • the association and dissociation curves were fitted to a 1:1 binding model using the data analysis software according to the manufacturer’s guidelines.
  • Example 13 Binding of humanized bispecific antibodies to human PD-L1 using ELISA Microtiter plates were coated with recombinant human PD-L1-msFc in PBS, and then blocked with 5% bovine serum albumin in PBS. Protein A purified anti-PD-L1 monoclonal antibody 9H9, bispecific antibodies 9H9-7A3 HL, 9H9-7A3 LH, 9H9-7B1 HL, 9H9-7B1 LH (as described in Example 11) and isotype controls were added at various concentrations and incubated at 37oC.
  • the plates were washed with PBS/Tween and then incubated with a goat- anti-human IgG Fc-specific polyclonal reagent conjugated to horseradish peroxidase at 37oC. After washing, the plates were developed with HRP substrate, and analyzed at OD 450 using a microtiter plate reader. Representative binding curves are shown in FIGs.12A and 12B.
  • Example 14 Binding of humanized bispecific antibodies to cells expressing human PD- L1 Protein A purified monoclonal antibodies, bispecific antibodies (9H9-7A3 HL, 9H9- 7A3 LH, 9H9-7B1 HL, 9H9-7B1 LH, as described in Example 11) and isotype controls were incubated with HEK293 cells expressing human PD-L1 at room temperature on a plate shaker. After 20 minutes, the cells were washed with PBS containing 0.1% BSA and 0.05% NaN3 (PBA) and the bound antibodies were detected by incubating the cells with a PE labeled goat anti-human IgG Fc-specific probe.
  • PBA PBS containing 0.1% BSA and 0.05% NaN3
  • Example 15 Binding of humanized bispecific antibodies to cells expressing human ILT4 Protein A purified monoclonal antibodies, bispecific monoclonal antibodies (9H9- 7A3 HL, 9H9-7A3 LH, 9H9-7B1 HL, 9H9-7B1 LH, as described in Example 11) and isotype controls were incubated with HEK293 cells expressing human ILT4 at room temperature on a plate shaker.
  • the cells were washed with PBS containing 0.1% BSA and 0.05% NaN3 (PBA) and the bound antibodies were detected by incubating the cells with a PE labeled goat anti-human IgG Fc-specific probe.
  • PBA PBS containing 0.1% BSA and 0.05% NaN3
  • the excess probe was washed from the cells with PBA and the cell associated fluorescence was determined by analysis using a FACSCanto II TM instrument (BD Biosciences, NJ, USA) according to the manufacturer’s directions. Representative binding curves are shown in FIGs.14A and 14B.
  • Example 16 Bifunctional binding of humanized bispecific antibodies to cell-expressed human ILT4 and to human PD-L1 Binding of bispecific constructs to ILT4 and PD-L1 was assessed using HEK293 cells expressing human ILT4. In brief, dilutions of the bispecific constructs were allowed to bind to the ILT4 expressing cell before adding human PD-L1-msFc that was detected with PE labeled goat anti-mouse IgG Fc-specific probe. Representative binding curves for four bispecific constructs (9H9-7A3 HL, 9H9-7A3 LH, 9H9-7B1 HL, and 9H9-7B1 LH, as described in Example 11) are shown in FIGs.15A and 15B.
  • Example 17 T cell PD1/PD-L1 blockade of humanized bispecific antibodies
  • the effect of the bispecific antibodies (9H9-7A3 HL, 9H9-7A3 LH, 9H9-7B1 HL, 9H9-7B1 LH, as described in Example 11) on blockade of the PD1/PD-L1 interaction was determined using the commercially available PD-1/PD-L1 Blockade Assay from Promega®. Two engineered cell lines, PD1 Effector cells and PD-L1 aAPC/CHO-K1 cells were co- cultured in the presence of the antibodies for 6 hours.
  • Blocking of the PD1/PD-L1 interaction results in TCR activation and induces luminescence via the NFAT pathway.
  • Luminescence was detected by the addition of Bio-Glo reagent and quantitated on a Perkin Elmer® Victor X4 luminometer.
  • the anti-PD-L1 antibodies and bispecific antibodies effectively block the PD1/PD-L1 interaction between cells leading to activation of the NFAT pathway.
  • Example 18 Induction of TNF- ⁇ production by humanized bispecific antibodies in macrophages
  • Macrophages were derived from human monocytes as follows: PBMC’s were added to a T175cm 2 flasks and monocytes allowed to adhere for ⁇ 2 hours at 37 o C, 6%CO2. The non-adherent cells were removed and the monocytes cultured for 7 days in RPMI containing 10% FBS and 50 ng/mL M-CSF (R&D Systems).
  • the cells were then incubated in the presence of the bispecific antibodies (9H9-7A3 HL, 9H9-7A3 LH, 9H9-7B1 HL, 9H9-7B1 LH, as described in Example 11) and the appropriate antibody controls with 50ng/mL LPS (Invivogen) at 37 o C, 6%CO2. After 24 hours, the cells were harvested and the supernatant was collected and stored for cytokine analysis. Induction of TNF- ⁇ was evaluated in the supernatants collected by ELISA (R&D Systems). FIGs.17A and 17B show the increase in TNF- ⁇ production with the bispecific antibodies.
  • Example 19 Inhibition of HLA-G binding to ILT4 by humanized bispecific antibodies Dilutions of the bispecific antibodies (9H9-7A3 HL, 9H9-7A3 LH, 9H9-7B1 HL, 9H9-7B1 LH, as described in Example 11) and antibody controls were incubated on HEK293 cells expressing human ILT4 at room temperature on a plate shaker. After 30 minutes, the cells were washed and PE-labeled HLA-G tetramer (FredHutch) was added.
  • FredHutch PE-labeled HLA-G tetramer

Abstract

L'invention concerne de nouveaux anticorps ILT4 et des fragments de liaison à l'antigène de ceux-ci, ainsi que des constructions bispécifiques et multispécifiques se liant à ILT4 et PD-L1, comprenant de tels anticorps liés à au moins un agent de liaison supplémentaire. Des procédés d'induction ou d'amélioration d'une réponse immunitaire, et des méthodes de traitement du cancer, par administration des anticorps (ou fragments), de constructions bispécifiques ou de compositions sont également décrits.
EP22720158.9A 2021-04-09 2022-04-08 Anticorps contre l'anticorps ilt4, anti-ilt4/pd-l1 bispécifique et ses utilisations Pending EP4320159A1 (fr)

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Family Cites Families (45)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4475196A (en) 1981-03-06 1984-10-02 Zor Clair G Instrument for locating faults in aircraft passenger reading light and attendant call control system
US4447233A (en) 1981-04-10 1984-05-08 Parker-Hannifin Corporation Medication infusion pump
US4439196A (en) 1982-03-18 1984-03-27 Merck & Co., Inc. Osmotic drug delivery system
US4866034A (en) 1982-05-26 1989-09-12 Ribi Immunochem Research Inc. Refined detoxified endotoxin
US4436727A (en) 1982-05-26 1984-03-13 Ribi Immunochem Research, Inc. Refined detoxified endotoxin product
US4522811A (en) 1982-07-08 1985-06-11 Syntex (U.S.A.) Inc. Serial injection of muramyldipeptides and liposomes enhances the anti-infective activity of muramyldipeptides
US4447224A (en) 1982-09-20 1984-05-08 Infusaid Corporation Variable flow implantable infusion apparatus
US4487603A (en) 1982-11-26 1984-12-11 Cordis Corporation Implantable microinfusion pump system
US4486194A (en) 1983-06-08 1984-12-04 James Ferrara Therapeutic device for administering medicaments through the skin
US4596556A (en) 1985-03-25 1986-06-24 Bioject, Inc. Hypodermic injection apparatus
FI861417A0 (fi) 1985-04-15 1986-04-01 Endotronics Inc Hepatitis b ytantigen framstaelld med rekombinant-dna-teknik, vaccin, diagnostiskt medel och cellinjer samt foerfaranden foer framstaellning daerav.
US5374548A (en) 1986-05-02 1994-12-20 Genentech, Inc. Methods and compositions for the attachment of proteins to liposomes using a glycophospholipid anchor
MX9203291A (es) 1985-06-26 1992-08-01 Liposome Co Inc Metodo para acoplamiento de liposomas.
US4676980A (en) 1985-09-23 1987-06-30 The United States Of America As Represented By The Secretary Of The Department Of Health And Human Services Target specific cross-linked heteroantibodies
GB8601597D0 (en) 1986-01-23 1986-02-26 Wilson R H Nucleotide sequences
US4877611A (en) 1986-04-15 1989-10-31 Ribi Immunochem Research Inc. Vaccine containing tumor antigens and adjuvants
US4790824A (en) 1987-06-19 1988-12-13 Bioject, Inc. Non-invasive hypodermic injection device
US4941880A (en) 1987-06-19 1990-07-17 Bioject, Inc. Pre-filled ampule and non-invasive hypodermic injection device assembly
EP1088830A3 (fr) 1987-06-22 2004-04-07 Medeva Holdings B.V. Particules de l'antigène de surface de l'hépatitie B
GB8717430D0 (en) 1987-07-23 1987-08-26 Celltech Ltd Recombinant dna product
GB8809129D0 (en) 1988-04-18 1988-05-18 Celltech Ltd Recombinant dna methods vectors and host cells
US4912094B1 (en) 1988-06-29 1994-02-15 Ribi Immunochem Research Inc. Modified lipopolysaccharides and process of preparation
JP3237842B2 (ja) 1988-12-16 2001-12-10 オランダ国 ニューモリシンミュータント及びそれから製造されたニューモコッカルワクチン
US5108921A (en) 1989-04-03 1992-04-28 Purdue Research Foundation Method for enhanced transmembrane transport of exogenous molecules
EP0414374B1 (fr) 1989-07-25 1997-10-08 Smithkline Biologicals S.A. Antigènes ainsi que les méthodes pour leur préparation
US5064413A (en) 1989-11-09 1991-11-12 Bioject, Inc. Needleless hypodermic injection device
US5312335A (en) 1989-11-09 1994-05-17 Bioject Inc. Needleless hypodermic injection device
US5383851A (en) 1992-07-24 1995-01-24 Bioject Inc. Needleless hypodermic injection device
CA2194761C (fr) 1994-07-15 2006-12-19 Arthur M. Krieg Oligonucleotides immunomodulateurs
WO1996026277A1 (fr) 1995-02-24 1996-08-29 Cantab Pharmaceuticals Research Limited Polypeptides utiles comme agents immunotherapeutiques et procedes de preparation de polypeptides
IL117483A (en) 1995-03-17 2008-03-20 Bernard Brodeur MENINGITIDIS NEISSERIA shell protein is resistant to proteinase K.
US5843464A (en) 1995-06-02 1998-12-01 The Ohio State University Synthetic chimeric fimbrin peptides
US7341727B1 (en) 1996-05-03 2008-03-11 Emergent Product Development Gaithersburg Inc. M. catarrhalis outer membrane protein-106 polypeptide, methods of eliciting an immune response comprising same
US5856462A (en) 1996-09-10 1999-01-05 Hybridon Incorporated Oligonucleotides having modified CpG dinucleosides
KR100619350B1 (ko) 1997-07-21 2006-09-05 박스터 헬쓰케어 에스.에이. 변형 면역성 뉴멀리신 백신조성물
GB9727262D0 (en) 1997-12-24 1998-02-25 Smithkline Beecham Biolog Vaccine
WO1999052549A1 (fr) 1998-04-09 1999-10-21 Smithkline Beecham Biologicals S.A. Compositions adjuvantes
EP1303299B1 (fr) 2000-03-29 2010-07-28 The Trustees of The University of Pennsylvania Utilisation des peptides prokaryotic pest-like pour augmenter l'immunogénicité des antigènes
US7560534B2 (en) 2000-05-08 2009-07-14 Celldex Research Corporation Molecular conjugates comprising human monoclonal antibodies to dendritic cells
LT2439273T (lt) 2005-05-09 2019-05-10 Ono Pharmaceutical Co., Ltd. Žmogaus monokloniniai antikūnai prieš programuotos mirties 1(pd-1) baltymą, ir vėžio gydymo būdai, naudojant vien tik anti-pd-1 antikūnus arba derinyje su kitais imunoterapiniais vaistais
NZ585556A (en) 2007-11-07 2012-07-27 Celldex Therapeutics Inc Antibodies that bind human dendritic and epithelial cell 205 (dec-205)
WO2016111947A2 (fr) * 2015-01-05 2016-07-14 Jounce Therapeutics, Inc. Anticorps inhibiteurs d'interactions de tim-3:lilrb2 et leurs utilisations
TWI796329B (zh) * 2017-04-07 2023-03-21 美商默沙東有限責任公司 抗－ilt4抗體及抗原結合片段
KR20210011919A (ko) 2018-04-17 2021-02-02 셀덱스 쎄라퓨틱스, 인크. 항-cd27 항체 및 항-pd-l1 항체 및 이중특이적 작제물
MA53381A (fr) * 2018-07-24 2021-06-02 Amgen Inc Association d'inhibiteurs de la voie lilrb1/2 et d'inhibiteurs de la voie pd-1

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